Merge "Add acov-llvm.py script" am: 40222a7d47 am: df1bd10d38 am: 3e6358267d

Original change: https://android-review.googlesource.com/c/platform/development/+/1654313

Change-Id: I8f83d9c55afb3630573ba5fb1df318c24f10a9a8