API Cleanup: Remove VideoState class.

- Remove VideoState class.
- Replace references to VideoState constants with VideoProfile equivalent.
- Push VideoState static methods into VideoProfile.

Bug: 21573551
Change-Id: I1bca02772b5b7d86643f612824b07faef7618725

telecomm/java/android/telecom/Conference.java

@@ -206,7 +206,7 @@ public abstract class Conference extends Conferenceable {
      * Returns video state of the primary call.
      */
     public int getVideoState() {
-        return VideoProfile.VideoState.AUDIO_ONLY;
+        return VideoProfile.STATE_AUDIO_ONLY;
     }
 
     /**