Populate buckets to ensure correct corner rounds on notifications

Fixes: 204127880
Bug: 200956118
Bug: 199388061
Test: manual
Test: atest SystemUITests:ShadeListBuilderTest SystemUITests:NotifSpecBuilderTest

Merged-In: I36f6f2ac2a503daa01594248a1e6cffcfbd5c348
Change-Id: I36f6f2ac2a503daa01594248a1e6cffcfbd5c348
18 files changed