Change MODIFY_AUDIO_ROUTING permission to MEDIA_CONTENT_CONTROL

As changing the permission for MediaRouter2 system APIs, this CL
changes the permission in shell accordingly.

The permission was added by ag/13959439.

Bug: 183428114
Test: Passed CTS tests
Change-Id: I3aee256a11db730dd786e69821f3bb8bd590074f
diff --git a/packages/Shell/AndroidManifest.xml b/packages/Shell/AndroidManifest.xml
index bef6423f..9c2e8c9 100644
--- a/packages/Shell/AndroidManifest.xml
+++ b/packages/Shell/AndroidManifest.xml
@@ -534,7 +534,7 @@
     <uses-permission android:name="android.permission.SCHEDULE_PRIORITIZED_ALARM" />
 
     <!-- Permission required for CTS test - SystemMediaRouter2Test -->
-    <uses-permission android:name="android.permission.MODIFY_AUDIO_ROUTING" />
+    <uses-permission android:name="android.permission.MEDIA_CONTENT_CONTROL" />
 
     <!-- Permission required for CTS test - CtsRotationResolverServiceDeviceTestCases -->
     <uses-permission android:name="android.permission.MANAGE_ROTATION_RESOLVER" />