4327 [camera] Bump minimum Flutter version and iOS deployment target (cla: yes, waiting for tree to go green, p: camera, platform-ios)

4342 [camera_web] Release the camera stream used to request video and audio permissions (cla: yes, waiting for tree to go green, p: camera, platform-web)

4358 [camera_platform_interface] Add web-relevant docs (cla: yes, waiting for tree to go green, p: camera)

4362 [camera] Remove iOS 9 availability check around ultra high capture sessions (cla: yes, waiting for tree to go green, p: camera, platform-ios)

4367 Require authors file (cla: yes, p: camera, p: in_app_purchase, p: quick_actions, platform-ios, platform-android, platform-web)