Fix how displays are used in test cases am: 017cb98ee9 am: 1186b99120 am: ed6ebed9f3 am: 819113071d

Original change: https://android-review.googlesource.com/c/platform/hardware/interfaces/+/2305821

Change-Id: I41e5a4059d7e0b56c6329b63d86cea0e4d495552
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>