Merge "Add an extra transition type in TransitSession for custom transition."...

Merge "Add an extra transition type in TransitSession for custom transition." into udc-dev am: e4c4d532

Original change: https://googleplex-android-review.googlesource.com/c/platform/frameworks/base/+/22802760



Change-Id: I1edd9c10e8fee5d439c842aaca3daab189e041ba
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>