Support for AGP 9.0

[pratiksahu18]

Feature description

Is it possible to add support for AGP 9.0? I have made the changes locally and tested as well. I can raise the PR or any contributors can make the changes

Reasoning

Benefit of this will be that plugin will be usable in new AGP 9.0+

[scorpeeon]

Agreed, it looks like as things stand it's not possible to use this on AGP9 with newDsl=true.

Running an analysis this problem might be even fixed on the main branch:
App Size Ruler is failing because Spotify Ruler 2.0.0-beta-3 (latest published) still casts the android extension to legacy BaseExtension in RulerTask.kt:128, which is hidden when newDsl=true. The fix exists on Ruler's main branch (uses ApplicationAndroidComponentsExtension) but Spotify hasn't published a release in ~18 months.

Would it be possible to publish a new release with these recent changes?