Fix ANR in SliceRelayReceiver

The same broadcast are handled in SliceRelayReceiver and WifiScanWorker.
We will only use WifiScanWorker to handle wifi broadcast.

Change-Id: I32c2fcc699ae240f12bd1049ba33e1792ae123b0
Fixes: 120284615
Test: manual

src/com/android/settings/slices/SliceBackgroundWorker.java

@@ -58,6 +58,10 @@ public abstract class SliceBackgroundWorker<E> implements Closeable {
         mUri = uri;
     }
 
+    public Uri getUri() {
+        return mUri;
+    }
+
     /**
      * Returns the singleton instance of the {@link SliceBackgroundWorker} for specified {@link
      * CustomSliceable}