Convert switcher4.py to python 3 am: 9ae90f6ff9

Original change: https://android-review.googlesource.com/c/platform/tools/doc_generation/+/1935069

Change-Id: Ie258fdaf6118ae45ae0b3250bfbd8739dedae2df
tree: f0cee68420551e1e2e9d21d7af7eab3ae9490e52
  1. Android.bp
  2. switcher4.py