[Mono.Android] Bind Android API-Baklava DP2. (#9653)

Context: https://developer.android.com/about/versions/16
Context: https://android-developers.googleblog.com/2024/12/second-developer-preview-android16.html

Android 16 Developer Preview 2 has been released.

  * [API-Baklava Developer Preview 2 vs. API-35][0]
  * [API-Baklava Developer Preview 2 vs. Developer Preview 1][1]

The Android 16 Developer Preview Program Overview
[Timeline and updates][2] section suggests the following timeline:

  * Nov/Dec: Developer Previews
  * Jan/Feb: Unstable Betas
  * Mar/Apr: Stable Betas
  * ???: Final

Currently, this will be usable in its preview form to `main` users
who explicitly target `net9.0-android36`.  Once we are shipping
.NET 10 previews, it will be usable for users who explicitly target
`net10.0-android36`.

We still need to decide on our strategy for backporting this to
.NET 9 service releases.

`PublicApiAnalyzers` reports 2 categories of API changes in
`PublicAPI.Shipped.txt`:

  - Method changed from `virtual` to `override`
  - Method parameter name changes, technically a source breaking
    change, but something we've never tracked or fixed before

[0]: https://developer.android.com/sdk/api_diff/b-dp1/changes
[1]: https://developer.android.com/sdk/api_diff/b-dp2-incr/changes
[2]: https://developer.android.com/about/versions/16/overview

build-tools/xaprepare/xaprepare/ConfigAndData/Dependencies/AndroidToolchain.cs

@@ -73,7 +73,7 @@ public AndroidToolchain ()
 				new AndroidPlatformComponent ("platform-33-ext3_r03",   apiLevel: "33", pkgRevision: "3"),
 				new AndroidPlatformComponent ("platform-34-ext7_r02",   apiLevel: "34", pkgRevision: "2"),
 				new AndroidPlatformComponent ("platform-35_r01",   apiLevel: "35", pkgRevision: "1", isLatestStable: true),
-				new AndroidPlatformComponent ("platform-Baklava_r01",   apiLevel: "Baklava", pkgRevision: "1", isLatestStable: true),
+				new AndroidPlatformComponent ("platform-Baklava_r03",   apiLevel: "Baklava", pkgRevision: "3", isLatestStable: true),
 
 				new AndroidToolchainComponent ("sources-34_r01",
 					destDir: Path.Combine ("sources", "android-34"),