Define UiEvents for communal hub

Test: n/a
Flag: n/a
Bug: 317798442
Bug: 318739657
Bug: 317798444
Bug: 317798384
Bug: 317798332
Bug: 317910348
Bug: 317798446
Bug: 317798387
Bug: 317798094
Bug: 317798096
Bug: 317798917
Change-Id: I2f96376dbf398b1f868841abf6e6023c04ffa457