aconfig for CarSystemUI must be in system_ext container am: 51415e3a8b

Original change: https://android-review.googlesource.com/c/platform/packages/apps/Car/SystemUI/+/3475913

Change-Id: I930d38eea6c222093cdd24cbc4ec00b7ec53c0a2
Signed-off-by: Automerger Merge Worker