Bump external/xamarin-android-tools from 6575743 to 11fad9d (#1250)

Bumps [external/xamarin-android-tools](https://github.com/xamarin/xamarin-android-tools) from `6575743` to `11fad9d`.
- [Commits](dotnet/android-tools@6575743...11fad9d)

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

Signed-off-by: dependabot[bot] <[email protected]>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

Author: dependabot[bot]