First pass at a swipe-through media view for conversations.
Future work could include
- title label per item
- sender name
- date/time
- photo rail
- include caption
// FREEBIE
- sync speakerphone state manipulated from system call screen
- Revert audio session after call failure, ensures media plays out of
speaker after placing a failing call.
- Replace notification with delegate pattern since we're already using
delegate pattern here.
- Fixes voiceover accessibility after voice memo
- Avoid audio blip after pressing hangup
- Rename CallAudioSession -> OWSAudioSession
Going to start using it for other non-call things since we want to
gather all our audio session concerns.
- Resume background audio when done playing video
- Extract OWSVideoPlayer which ensures audio is in proper state before
playback
- Move recording session logic to shared OWSAudioSession
- Deactivate audio session when complete
// FREEBIE
