Add flag for onWlcStateChanged

Fix the warnging in ag/25090760

Bug: 292143899
Test: compiles
Change-Id: I6a712a0bdcd37815f0adaaa5bd3f6fd28962788b
diff --git a/nfc/java/android/nfc/NfcWlcStateListener.java b/nfc/java/android/nfc/NfcWlcStateListener.java
index 8d79310..2cde5e5 100644
--- a/nfc/java/android/nfc/NfcWlcStateListener.java
+++ b/nfc/java/android/nfc/NfcWlcStateListener.java
@@ -98,8 +98,10 @@
             Executor executor = mListenerMap.get(listener);
             final long identity = Binder.clearCallingIdentity();
             try {
-                executor.execute(() -> listener.onWlcStateChanged(
-                        mCurrentState));
+                if (Flags.enableNfcCharging()) {
+                    executor.execute(() -> listener.onWlcStateChanged(
+                            mCurrentState));
+                }
             } finally {
                 Binder.restoreCallingIdentity(identity);
             }