[Audiosharing] Hide / show audio streams category.

Only show when there is an active LE buds connecting, and the source is
not currently broadcasting.

Bug: 308368124
Test: Manual
Change-Id: I2cc172a66648901ac8a7e49c5aac734b6bbc7e33

src/com/android/settings/connecteddevice/audiosharing/AudioSharingBasePreferenceController.java

@@ -64,7 +64,7 @@ public abstract class AudioSharingBasePreferenceController extends BasePreferenc
         mPreference.setVisible(isVisible);
     }
 
-    private boolean isBroadcasting() {
+    protected boolean isBroadcasting() {
         return mBroadcast != null && mBroadcast.isEnabled(null);
     }
 }