Add license files am: 1b80a8f61e am: a42ceb3e06 am: 6a0d0a5fda am: c900ce84c8

Original change: https://android-review.googlesource.com/c/platform/external/nullaway/+/1972865

Change-Id: I4d8f1889960d4bd8d61f015a95cae6b567fea353