[Mono.Android] Fix Context.RegisterReceiver() enumification (#7735)

Fixes: #7503

Context: e33eb53
Context: df6c716
Context: 76ab8b2

The bindings for
[`Context.registerReceiver(BroadcastReceiver, IntentFilter, int)`][0]
and related overloads incorrectly enumified the `int` parameter as
the `Android.Content.ActivityFlags` enum (e33eb53), when it should
have been `Android.Content.ReceiverFlags` (df6c716).

Unfortunately we can't directly fix this, as the bound
`Context.RegisterReceiver(BroadcastReceiver, IntentFilter, ActivityFlags)`
method is *`abstract`*, and thus changing it would break compatibility.

Fix this without breaking API by:

 1. Creating new overload methods which chain to the existing methods
 2. Mark the existing methods and method overrides as `[Obsolete]`.

a'la:

	partial class Context {
	    [Obsolete ("This method has an incorrect enumeration type. Use the overload that takes ReceiverFlags instead.")]
	    public abstract Intent? RegisterReceiver (BroadcastReceiver? receiver, IntentFilter? filter, [GeneratedEnum] ActivityFlags flags);

	    public Intent? RegisterReceiver (BroadcastReceiver? receiver, IntentFilter? filter, ReceiverFlags flags) =>
	        RegisterReceiver (receiver, filter, (ActivityFlags)flags);
	}

A concern with this approach is that it means that a public `abstract`
method is now `[Obsolete]`, which would make it "weird" to override.
However, this is a method that should *never* be overridden by user
code, so we think this is an acceptable compromise.

Additionally, it was noticed that the public API tracking added in
76ab8b2 did not flag this change as an error, only a warning.
Convert the RS0016 and RS0017 warnings into errors to ensure that any
new public API is accounted for.

[0]: https://developer.android.com/reference/android/content/Context#registerReceiver(android.content.BroadcastReceiver,%20android.content.IntentFilter,%20int)

src/Mono.Android/Android.Content/Context.cs

@@ -1,4 +1,5 @@
 using System;
+using Android.OS;
 using Android.Runtime;
 
 namespace Android.Content {
@@ -16,5 +17,14 @@ public void StartActivity (Type type)
 		[Obsolete ("This constant will be removed in the future version. Use Android.Content.ReceiverFlags enum directly instead of this field.")]
 		public const int ReceiverVisibleToInstantApps = 1;
 #endif
+
+#if ANDROID_34
+		// Add correctly enumified overloads
+		public Intent? RegisterReceiver (BroadcastReceiver? receiver, IntentFilter? filter, ReceiverFlags flags)
+			=> RegisterReceiver (receiver, filter, (ActivityFlags)flags);
+
+		public Intent? RegisterReceiver (BroadcastReceiver? receiver, IntentFilter? filter, string? broadcastPermission, Handler? scheduler, ReceiverFlags flags)
+			=> RegisterReceiver (receiver, filter, broadcastPermission, scheduler, (ActivityFlags)flags);
+#endif
 	}
 }

src/Mono.Android/Mono.Android.csproj

@@ -27,7 +27,12 @@
   <PropertyGroup>
     <DefineConstants Condition=" '$(AndroidApiLevel)' &gt; '$(AndroidLatestStableApiLevel)' ">$(DefineConstants);ANDROID_UNSTABLE</DefineConstants>
     <OutputPath>$(_MonoAndroidNETDefaultOutDir)</OutputPath>
+
+    <!-- Allow PublicApiAnalyzers to be turned off -->
     <RunAnalyzers Condition=" '$(DisableApiCompatibilityCheck)' == 'True' ">false</RunAnalyzers>
+
+    <!-- PublicApiAnalyzers warnings should be errors, but building in VS throws incorrect extra warnings -->
+    <WarningsAsErrors Condition=" '$(BuildingInsideVisualStudio)' != 'True' ">$(WarningsAsErrors);RS0016,RS0017</WarningsAsErrors>
   </PropertyGroup>
 
   <PropertyGroup Condition=" '$(IncludeAndroidJavadoc)' == 'True' ">

src/Mono.Android/PublicAPI/API-34/PublicAPI.Unshipped.txt

@@ -8448,6 +8448,8 @@ Android.Content.Context.ObtainStyledAttributes(Android.Util.IAttributeSet? set,
 Android.Content.Context.ObtainStyledAttributes(Android.Util.IAttributeSet? set, int[]! attrs, int defStyleAttr, int defStyleRes) -> Android.Content.Res.TypedArray!
 Android.Content.Context.ObtainStyledAttributes(int resid, int[]! attrs) -> Android.Content.Res.TypedArray!
 Android.Content.Context.ObtainStyledAttributes(int[]! attrs) -> Android.Content.Res.TypedArray!
+Android.Content.Context.RegisterReceiver(Android.Content.BroadcastReceiver? receiver, Android.Content.IntentFilter? filter, Android.Content.ReceiverFlags flags) -> Android.Content.Intent?
+Android.Content.Context.RegisterReceiver(Android.Content.BroadcastReceiver? receiver, Android.Content.IntentFilter? filter, string? broadcastPermission, Android.OS.Handler? scheduler, Android.Content.ReceiverFlags flags) -> Android.Content.Intent?
 Android.Content.Context.StartActivity(System.Type! type) -> void
 Android.Content.ContextParams
 Android.Content.ContextParams.AttributionTag.get -> string?

src/Mono.Android/metadata

@@ -1809,6 +1809,14 @@
 
   <!-- 2 conflicting copies of ErrorEventArgs -->
   <attr api-since="34" path="/api/package[@name='android.speech']/interface[@name='ModelDownloadListener']/method[@name='onError' and count(parameter)=1 and parameter[1][@type='int']]" name="argsType">ModelDownloadErrorEventArgs</attr>
+
+  <!-- Fix some incorrectly enumified methods -->
+  <attr api-since="34" path="/api/package[@name='android.content']/class[@name='Context']/method[@name='registerReceiver' and count(parameter)=3 and parameter[1][@type='android.content.BroadcastReceiver'] and parameter[2][@type='android.content.IntentFilter'] and parameter[3][@type='int']]" name="deprecated">This method has an incorrect enumeration type. Use the overload that takes ReceiverFlags instead.</attr>
+  <attr api-since="34" path="/api/package[@name='android.content']/class[@name='Context']/method[@name='registerReceiver' and count(parameter)=5 and parameter[1][@type='android.content.BroadcastReceiver'] and parameter[2][@type='android.content.IntentFilter'] and parameter[3][@type='java.lang.String'] and parameter[4][@type='android.os.Handler'] and parameter[5][@type='int']]" name="deprecated">This method has an incorrect enumeration type. Use the overload that takes ReceiverFlags instead.</attr>
+  <attr api-since="34" path="/api/package[@name='android.content']/class[@name='ContextWrapper']/method[@name='registerReceiver' and count(parameter)=3 and parameter[1][@type='android.content.BroadcastReceiver'] and parameter[2][@type='android.content.IntentFilter'] and parameter[3][@type='int']]" name="deprecated">This method has an incorrect enumeration type. Use the overload that takes ReceiverFlags instead.</attr>
+  <attr api-since="34" path="/api/package[@name='android.content']/class[@name='ContextWrapper']/method[@name='registerReceiver' and count(parameter)=5 and parameter[1][@type='android.content.BroadcastReceiver'] and parameter[2][@type='android.content.IntentFilter'] and parameter[3][@type='java.lang.String'] and parameter[4][@type='android.os.Handler'] and parameter[5][@type='int']]" name="deprecated">This method has an incorrect enumeration type. Use the overload that takes ReceiverFlags instead.</attr>
+  <attr api-since="34" path="/api/package[@name='android.test.mock']/class[@name='MockContext']/method[@name='registerReceiver' and count(parameter)=3 and parameter[1][@type='android.content.BroadcastReceiver'] and parameter[2][@type='android.content.IntentFilter'] and parameter[3][@type='int']]" name="deprecated">This method has an incorrect enumeration type. Use the overload that takes ReceiverFlags instead.</attr>
+  <attr api-since="34" path="/api/package[@name='android.test.mock']/class[@name='MockContext']/method[@name='registerReceiver' and count(parameter)=5 and parameter[1][@type='android.content.BroadcastReceiver'] and parameter[2][@type='android.content.IntentFilter'] and parameter[3][@type='java.lang.String'] and parameter[4][@type='android.os.Handler'] and parameter[5][@type='int']]" name="deprecated">This method has an incorrect enumeration type. Use the overload that takes ReceiverFlags instead.</attr>
 
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