Add the language switcher to the packages and classes pages for the Android Platform. am: 775276b773 am: 1c64cfff16

Original change: https://android-review.googlesource.com/c/platform/tools/doc_generation/+/1433212

Change-Id: Ic0cf20a0e109247637497456accf5fb800e85b66
tree: f95263c33a855c69a499c737fe82a0ab9970ddd7
  1. Android.bp
  2. switcher4.py