Suppress the warnings in EffectRecorder

Change-Id: I29d8348f40c35e720ab230e2c599bf8a8ff2a953
diff --git a/proguard.flags b/proguard.flags
index 8250933..66e5367 100644
--- a/proguard.flags
+++ b/proguard.flags
@@ -32,3 +32,6 @@
 -keep class com.android.camera.CameraHolder {
   public static void injectMockCamera(...);
 }
+
+# Disable the warnings of using dynamic method calls in EffectsRecorder
+-dontnote com.android.camera.EffectsRecorder