Merge "Add support for onReject and onError for external hotword." into tm-dev am: 90579f32 am: 654794a9

Original change: https://googleplex-android-review.googlesource.com/c/platform/frameworks/base/+/18308197



Change-Id: I149972a9239a4503207893588b754f20e26cd794
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>