Merge "Better error message in case of multiple splits." into udc-dev am: 413bb027b1

Original change: https://googleplex-android-review.googlesource.com/c/platform/frameworks/base/+/23179125

Change-Id: I4dbcdfaa14de68dd4e5727cfa04932be08fcf400
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>