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

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

Change-Id: Ic5a3933d960da25bc800434cb7b776a02ce09f99
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>