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

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

Change-Id: I828ddd434a176aa5de13387745f31d1964e595dd
tree: f95263c33a855c69a499c737fe82a0ab9970ddd7
  1. Android.bp
  2. switcher4.py