Fix permission hole for RECORD_AUDIO created when we moved the MediaRecorder

implementation to the mediaserver process. The permission check was previously
enforced only at the AudioRecord binder interface for clients not in the same
process. This change adds an additional check when the client tries to set
the audio source.
Bug 1868334

media/libmediaplayerservice/MediaRecorderClient.cpp

@@ -37,6 +37,7 @@
 namespace android {
 
 const char* cameraPermission = "android.permission.CAMERA";
+const char* recordAudioPermission = "android.permission.RECORD_AUDIO";
 
 static bool checkPermission(const char* permissionString) {
 #ifndef HAVE_ANDROID_OS
@@ -86,6 +87,9 @@ status_t MediaRecorderClient::setVideoSource(int vs)
 status_t MediaRecorderClient::setAudioSource(int as)
 {
     LOGV("setAudioSource(%d)", as);
+    if (!checkPermission(recordAudioPermission)) {
+        return PERMISSION_DENIED;
+    }
     Mutex::Autolock lock(mLock);
     if (mRecorder == NULL)  {
         LOGE("recorder is not initialized");