fix: Sometimes startRingtone() would throw java.lang.UnsupportedOperationException

Author: Ricardo Corrie

android/src/main/java/com/zxcpoiu/incallmanager/InCallManagerModule.java

@@ -951,7 +951,7 @@ public void run() {
                     }
 
                     if (audioManagerActivated) {
-                        stop();
+                        InCallManagerModule.this.stop();
                     }
 
                     wakeLockUtils.acquirePartialWakeLock();