Checking if multicastLock isHeld before trying to release it, avoiding stopServiceDiscovery call if discovery failed to start

Author: sharadb-amazon

examples/tv-casting-app/android/App/app/src/main/jni/com/chip/casting/NsdDiscoveryListener.java

@@ -111,7 +111,6 @@ public void onStartDiscoveryFailed(String serviceType, int errorCode) {
     failureCallback.handle(
         new MatterError(
             3, "NsdDiscoveryListener Discovery failed to start: Nsd Error code:" + errorCode));
-    nsdManager.stopServiceDiscovery(this);
   }
 
   @Override
@@ -123,6 +122,5 @@ public void onStopDiscoveryFailed(String serviceType, int errorCode) {
     failureCallback.handle(
         new MatterError(
             3, "NsdDiscoveryListener Discovery failed to stop: Nsd Error code:" + errorCode));
-    nsdManager.stopServiceDiscovery(this);
   }
 }

examples/tv-casting-app/android/App/app/src/main/jni/com/chip/casting/TvCastingApp.java

@@ -137,7 +137,9 @@ public void discoverVideoPlayerCommissioners(
               public void run() {
                 Log.d(TAG, "TvCastingApp stopping Video Player commissioner discovery");
                 nsdManager.stopServiceDiscovery(nsdDiscoveryListener);
-                multicastLock.release();
+                if (multicastLock.isHeld()) {
+                  multicastLock.release();
+                }
               }
             },
             discoveryDurationSeconds,