ios: fix audio route changed by webrtc when answered and related issue.
ios: fix audio route changed by webrtc when answered and related issue.

* fix audio route changed by webrtc when established
* ios now has function updateAudioRoute() similar to android.
* not override audioRoute to speaker for now. use Voice/Video Mode instead
  but we may reuse it if we want to force speaker on even when wired
  headset is plugged.

zxcpoiu/react-native-incall-manager,zxcpoiu/react-native-incall-manager,zxcpoiu/react-native-incall-manager