IssueTracker

Right now there is experimental support for extension libraries using system properties com.android.tools.r8.androidApiExtensionLibraries and com.android.tools.r8.androidApiExtensionPackages.

We should add a supported API and CLI option for this. Passing the jars (as with com.android.tools.r8.androidApiExtensionLibraries) seems to be the best way. When building targeting extension APIs there will be jars with these APIs currently passed as classpath to the compilation.

I have duplicated b/364277459 into this, as with a supported API there should be dump support.