[automerger skipped] Move display mocking tests to DisplayServiceTests am: d790d2dbf5 -s ours

am skip reason: Merged-In I242371f84185b1f770554a5ae0fbab6ed287a86f with SHA-1 eeb677c9d5 is already in history

Original change: https://googleplex-android-review.googlesource.com/c/platform/frameworks/base/+/24100525

Change-Id: I9d808534d20d23a97d76e7dd99b7e5bbdb12042a
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>