Handle missing sources for Android standard library

[pombredanne]

There is a significant number of standard library Java files that are part of the Android toolchain and are therefore not mapped as-is. We need to find a watch to either match or map or filter these for improved deployment and binary analysis. Things such as these classes in the android and androidx packages:

• to/classes.dex-out/sources/android/support/v4/graphics/drawable/IconCompatParcelizer.java
• to/classes.dex-out/sources/androidx/activity/Cancellable.java