Upgrade to Mockito v2.7.13

Renames README.android to README.version to match most common
use of the file name.

Deletes the compat classes, they will be added later, along
with an upstream patch.

Bug: 32912773
Test: see following commit
Change-Id: Iaa4d16b2a5a71955d7ecddf195ae681cf6505088
1099 files changed