Convert switcher4.py to python 3 am: 9ae90f6ff9 am: cb0539b94d am: af28506348 am: 762c910ca1

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

Change-Id: I7311d834ef1d4da65222c0dcd2a219c7f2eb9061