[automerger skipped] Merge "Allow empty tokens in strict grammar" into rvc-dev...

[automerger skipped] Merge "Allow empty tokens in strict grammar" into rvc-dev am: 5fa6de74 am: c4c71422 -s ours

am skip reason: Change-Id Iac1cdd643253fd186a164b863d65d6e92698fd38 with SHA-1 b7cffcab is in history

Original change: https://googleplex-android-review.googlesource.com/c/platform/frameworks/base/+/13554971

MUST ONLY BE SUBMITTED BY AUTOMERGER

Change-Id: I2644bd66fa481afdc57010eb81222375fa0b9e45