[automerger skipped] Fix kotlin nullable errors in frameworks/libs/systemui am: 6a3b93c3 -s ours am: 46120826 -s ours am: a12b385a -s ours

am skip reason: Merged-In If8dc1d32d7fd02e41c12cfb1571374c1e974e87c with SHA-1 b80daead is already in history

Original change: https://googleplex-android-review.googlesource.com/c/platform/frameworks/libs/systemui/+/24721695



Change-Id: I900fc54f76948c2aeb5ef7f4e4471be180969d0a
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>