audio policy: add permission for routing APIs.

Add check for signature or system permission
"android.permission.MODIFY_AUDIO_ROUTING" for routing
APIs.

Bug: 14815883.
Change-Id: Iefa0b9d90127a53e03a2e6d50dc93d8f4ae63e2f
diff --git a/services/audioflinger/ServiceUtilities.h b/services/audioflinger/ServiceUtilities.h
index 531bc56..df6f6f4 100644
--- a/services/audioflinger/ServiceUtilities.h
+++ b/services/audioflinger/ServiceUtilities.h
@@ -24,6 +24,7 @@
 bool captureAudioOutputAllowed();
 bool captureHotwordAllowed();
 bool settingsAllowed();
+bool modifyAudioRoutingAllowed();
 bool dumpAllowed();
 
 }