[automerger skipped] Refactor conference participant processing. am: f190b822 am: 30f898ef -s ours
am skip reason: Change-Id I5bc84ef388fa3ecc6d6c8440a82a3104c06d56c0 with SHA-1 3c5c7d22 is in history
Change-Id: I3c5756b4da288302100df91d805a665178125be3