[Xamarin.Android.Tools.AndroidSdk] Add JdkInfo.GetSupportedJdkInfos() (…

…#142)

Context: https://devdiv.visualstudio.com/DevDiv/_workitems/edit/1415418

Visual Studio needs to know the list of supported JDKs, so that it
can appropriately compare and display them to the user as part of a
"reset to defaults" experience.

The list of "supported" JDKs was formerly provided by the *`internal`*
`JdkInfo.GetPreferredJdkInfos()` method.

Rename `JdkInfo.GetPreferredJdkInfos()` to
`JdkInfo.GetSupportedJdkInfos()`, and make `public`.  The rename is
done to reduce ambiguity over what the "preferred" *means*, so that
in public APIs it only means "whatever the user has previously
selected, as per the Windows Registry/`monodroid-config.xml`/etc.

src/Xamarin.Android.Tools.AndroidSdk/AndroidSdkInfo.cs

@@ -185,7 +185,7 @@ public static void DetectAndSetPreferredJavaSdkPathToLatest (Action<TraceLevel,
 
 			logger          = logger ?? DefaultConsoleLogger;
 
-			var latestJdk   = JdkInfo.GetPreferredJdkInfos (logger).FirstOrDefault ();
+			var latestJdk   = JdkInfo.GetSupportedJdkInfos (logger).FirstOrDefault ();
 			if (latestJdk == null)
 				throw new NotSupportedException ("No Microsoft OpenJDK could be found.  Please re-run the Visual Studio installer or manually specify the JDK path in settings.");
 

src/Xamarin.Android.Tools.AndroidSdk/JdkInfo.cs

@@ -1,4 +1,4 @@
-using System;
+using System;
 using System.Collections.Generic;
 using System.Collections.ObjectModel;
 using System.Diagnostics;
@@ -280,7 +280,7 @@ static bool AnySystemJavasInstalled ()
 			return props;
 		}
 
-		// Keep ordering in sync w/ GetPreferredJdkInfos
+		// Keep ordering in sync w/ GetSupportedJdkInfos
 		public static IEnumerable<JdkInfo> GetKnownSystemJdkInfos (Action<TraceLevel, string>? logger = null)
 		{
 			logger  = logger ?? AndroidSdkInfo.DefaultConsoleLogger;
@@ -302,8 +302,10 @@ public static IEnumerable<JdkInfo> GetKnownSystemJdkInfos (Action<TraceLevel, st
 		}
 
 		// Keep ordering in sync w/ GetKnownSystemJdkInfos
-		internal static IEnumerable<JdkInfo> GetPreferredJdkInfos (Action<TraceLevel, string> logger)
+		public static IEnumerable<JdkInfo> GetSupportedJdkInfos (Action<TraceLevel, string>? logger = null)
 		{
+			logger = logger ?? AndroidSdkInfo.DefaultConsoleLogger;
+
 			return MicrosoftOpenJdkLocations.GetMicrosoftOpenJdks (logger)
 				.Concat (EclipseAdoptiumJdkLocations.GetEclipseAdoptiumJdks (logger))
 				.Concat (MicrosoftDistJdkLocations.GetMicrosoftDistJdks (logger))