am 152b4b6e: (-s ours) Merge "Support conference calling. (4/4) [DO NOT MERGE]" into lmp-preview-dev

* commit '152b4b6ed46982021b6bb9d2a0304eabaf74d7d2':
  Support conference calling. (4/4) [DO NOT MERGE]
tree: 1100941d0921549c774d7b0f6ef7472a92823406
  1. InCallUI/