[automerger skipped] Merge "Allow empty tokens in strict grammar" into rvc-dev am: c5c92421 am: d80b097d -s ours am: 23c005c6 -s ours

am skip reason: Change-Id Ie82dded77a3eaa75095333b0e77f10e21c9f7caf with SHA-1 a3986a5d is in history

Original change: https://googleplex-android-review.googlesource.com/c/platform/frameworks/base/+/13554969

MUST ONLY BE SUBMITTED BY AUTOMERGER

Change-Id: I5d3bc595435ffdbc57728de054584fc0b1cf4c57