ci: fix Android SDK setup

[jpnurmi]

This PR fixes the newly appeared Android SDK setup problem on Windows ARM64 due to a CI image OS update:

Warning: Dependant package with key emulator not found!
...
Warning: Unable to compute a complete list of dependencies.

https://github.com/getsentry/sentry-dotnet/actions/runs/16305149243/job/46070499645

Note

android-actions/setup-android uses a default value packages: tools platform-tools, where tools includes the Android Emulator, which is not available for Linux/Windows ARM64.

Fix attempts:

1. Install platform-tools alone ❌

   error XA5205: Cannot find `aapt.exe`. Please install the Android SDK Build-Tools package with the `C:\Users\runneradmin\.android\sdk\tools\android.bat` program.
   

2. Add build-tools;36.0.0 ❌

   error XA5207: Could not find android.jar for API level 34. This means the Android SDK platform for API level 34 is not installed; it was expected to be in `C:\Users\runneradmin\.android\sdk\platforms\android-34\android.jar`.
   error XA5207: Could not find android.jar for API level 35. This means the Android SDK platform for API level 35 is not installed; it was expected to be in `C:\Users\runneradmin\.android\sdk\platforms\android-35\android.jar`
   

3. Add platforms;android-34 platforms;android-35 ✅

#skip-changelog

[jpnurmi]

Here's the culprit summarized in one screenshot.

Even if partner-runner-images/arm-windows-11-image.md explicitly documents that Android SDK is not available, the old Windows ARM64 image did have the following ANDROID_XXX environment variables set:

ANDROID_HOME                   C:\Android\android-sdk
ANDROID_NDK                    C:\Android\android-sdk\ndk\27.2.12479018
ANDROID_NDK_HOME               C:\Android\android-sdk\ndk\27.2.12479018
ANDROID_NDK_LATEST_HOME        C:\Android\android-sdk\ndk\27.2.12479018
ANDROID_NDK_ROOT               C:\Android\android-sdk\ndk\27.2.12479018
ANDROID_SDK_ROOT               C:\Android\android-sdk

My theory: The old Windows ARM64 image might have had some semi-working Android SDK installation that was enough to make sentry-dotnet CI pass. Now that they have removed it, android-actions/setup-android tries to install it from scratch and fails.