DrmHalTest: null check for skipped test am: 9049fc93a8 am: efe8d1a7a4 am: 9b70745827

Original change: https://android-review.googlesource.com/c/platform/hardware/interfaces/+/2417394

Change-Id: If10cd3c29e13797340dfb74afae042f2a32ee4bf
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>