C.AudioFocusGain (ExoPlayer library)

```
@Documented
@Retention(SOURCE)
public static @interface C.AudioFocusGain
```
Audio focus types. One of C.AUDIOFOCUS_NONE, C.AUDIOFOCUS_GAIN, C.AUDIOFOCUS_GAIN_TRANSIENT, C.AUDIOFOCUS_GAIN_TRANSIENT_MAY_DUCK or C.AUDIOFOCUS_GAIN_TRANSIENT_EXCLUSIVE.