Merge "Fix NPE in TTS service if no engine string" into udc-dev am: 987b2e7d35 am: bd6c94ced7 am: c0b3d6bd69 am: 6451fb6c56

Original change: https://googleplex-android-review.googlesource.com/c/platform/frameworks/base/+/24758914

Change-Id: Id6c99b0039984233f80120d1dd7bc8558f4d1f3b
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>