MediaRouter: Route setBluetoothA2dpOn() via MediaRouterService

The direct binder usage of AudioService.setBluetoothA2dpOn() is now
blocked by permission for security reasons.
This CL routes the usage to the MediaRouterService.

Bug: 181962322, Bug: 189176702
Test: GMM can play navigation sound when BT is connected
Change-Id: Ib13c224a0d412ef6d802eeaadd246649c819c26f

media/java/android/media/IMediaRouterService.aidl

@@ -39,6 +39,7 @@ interface IMediaRouterService {
     MediaRouterClientState getState(IMediaRouterClient client);
     boolean isPlaybackActive(IMediaRouterClient client);
 
+    void setBluetoothA2dpOn(IMediaRouterClient client, boolean on);
     void setDiscoveryRequest(IMediaRouterClient client, int routeTypes, boolean activeScan);
     void setSelectedRoute(IMediaRouterClient client, String routeId, boolean explicit);
     void requestSetVolume(IMediaRouterClient client, String routeId, int volume);

media/java/android/media/MediaRouter.java

@@ -1070,7 +1070,8 @@ public class MediaRouter {
                 && (types & ROUTE_TYPE_LIVE_AUDIO) != 0
                 && (route.isBluetooth() || route.isDefault())) {
             try {
-                sStatic.mAudioService.setBluetoothA2dpOn(route.isBluetooth());
+                sStatic.mMediaRouterService.setBluetoothA2dpOn(sStatic.mClient,
+                        route.isBluetooth());
             } catch (RemoteException e) {
                 Log.e(TAG, "Error changing Bluetooth A2DP state", e);
             }

services/core/java/com/android/server/media/MediaRouterService.java

@@ -336,6 +336,25 @@ public final class MediaRouterService extends IMediaRouterService.Stub
         }
     }
 
+    // Binder call
+    @Override
+    public void setBluetoothA2dpOn(IMediaRouterClient client, boolean on) {
+        if (client == null) {
+            throw new IllegalArgumentException("client must not be null");
+        }
+
+        final long token = Binder.clearCallingIdentity();
+        try {
+            synchronized (mLock) {
+                mAudioService.setBluetoothA2dpOn(on);
+            }
+        } catch (RemoteException ex) {
+            Slog.w(TAG, "RemoteException while calling setBluetoothA2dpOn. on=" + on);
+        } finally {
+            Binder.restoreCallingIdentity(token);
+        }
+    }
+
     // Binder call
     @Override
     public void setDiscoveryRequest(IMediaRouterClient client,