[VTS] Update SetDisplayBrightness test item am: 70d2ef6b34

Original change: https://android-review.googlesource.com/c/platform/hardware/interfaces/+/2883951

Change-Id: Ia57991b0f949307764afeb9fe9fa58c67740900e
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>