Bump to dotnet/android-tools@c6fc83d (#1381)

Bumps [external/xamarin-android-tools](https://github.com/xamarin/xamarin-android-tools) from `062cc29` to `c6fc83d`.
- [Commits](dotnet/android-tools@062cc29...c6fc83d)

---
updated-dependencies:
- dependency-name: external/xamarin-android-tools
  dependency-version: c6fc83d94d08e6431e5415c327149912fdb77efa
  dependency-type: direct:production
...

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