Merge "Add a new test target for rollback observer." into main am: fe68c630 am: 238f6eb9

Original change: https://android-review.googlesource.com/c/platform/frameworks/base/+/2980871



Change-Id: I556fca601531a6cc3172114007b169b8501571b5
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>