Add IT for a project with `com.android.kotlin.multiplatform.library` plugin

[whyoleg]

Google recently introduced a new plugin that provides external Android support for Kotlin Multiplatform instead of androidTarget coming from KGP
Migration guide: https://developer.android.com/kotlin/multiplatform/plugin

We should add an IT for this kind of project, as this will be the future way of supporting Android in Kotlin Multiplatform projects, so Dokka should work properly with them.

[whyoleg]

Probably it would be nice to add all the same tests we have already, including the one from #4258.

[adam-enko]

There's an integration test for AGP 9 + KMP in my branch that adds support for AGP with Kotlin built-in.
master...adam/support-agp-kotlin-builtin