Merge "Mark SystemUI-tests as test code for lint" am: 0b33d054b3

Original change: https://android-review.googlesource.com/c/platform/frameworks/base/+/2184008

Change-Id: I0e3851927450aa4ef6e1a9d6623c04bbe6aeaef8
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>