generator needs to support non-integral versions

[jonpryor]

Context: dotnet/android#10438
Context: https://android-developers.googleblog.com/2025/08/android-16-qpr2-beta-1-is-here.html

The world of Android "minor" SDK versions is upon us! Which is a world in which new APIs are added, but the API level is not changed.

Which means integral API level names are inadequate; we need floating-point!

Update generator so that "minor" SDK versions such as "36.1" are now supported:

https://github.com/dotnet/java-interop/blob/main/tools/generator/SourceWriters/Extensions/SourceWriterExtensions.cs#L310-L329

This will likely require a fair bit of "plumbing" across the toolchain, as IIRC API levels are inferred from the merge.SourceFile attribute within API.xml:

<field deprecated="not deprecated" final="true" name="ACTION_CALL_BACK" jni-signature="Ljava/lang/String;" static="true" transient="false" type="java.lang.String" type-generic-aware="java.lang.String" value="&quot;android.telecom.action.CALL_BACK&quot;" visibility="public" volatile="false" merge.SourceFile="/Volumes/Xamarin-Work/src/dotnet/android/build-tools/create-android-api/../../bin/BuildDebug/api/api-CANARY.xml.in" />
<field deprecated="not deprecated" final="true" name="ACTION_CHANGE_DEFAULT_DIALER" jni-signature="Ljava/lang/String;" static="true" transient="false" type="java.lang.String" type-generic-aware="java.lang.String" value="&quot;android.telecom.action.CHANGE_DEFAULT_DIALER&quot;" visibility="public" volatile="false" merge.SourceFile="/Volumes/Xamarin-Work/src/dotnet/android/build-tools/create-android-api/../../bin/BuildDebug/api/api-23.xml.in" />

So we'll need a way to say "CANARY is 36.1" -- which presumably already exists, as e.g. API-BAKLAVA became API-36 -- and also update everything that "infers an API level from merge.SourceFile" to support non-integral values.

[jonpryor]

This was fixed in PR #1360.