Add new team members as owners of sdk/objc. Bug: None Change-Id: Id8c40fb018da2ab634bc1117afda555275a8b0f8 Reviewed-on: https://webrtc-review.googlesource.com/74002 Reviewed-by: Anders Carlsson <andersc@webrtc.org> Commit-Queue: Magnus Jedvert <magjed@webrtc.org> Cr-Commit-Position: refs/heads/master@{#23169}