PR fixes

Author: avishalom

auth/src/main/java/com/google/firebase/quickstart/AuthSnippets.java

@@ -1,7 +1,6 @@
 packagecom.google.firebase.quickstart;
 
 importcom.google.auth.oauth2.GoogleCredentials;
-importcom.google.common.collect.ImmutableMap;
 importcom.google.firebase.FirebaseApp;
 importcom.google.firebase.FirebaseOptions;
 importcom.google.firebase.auth.ExportedUserRecord;
@@ -244,7 +243,9 @@ public static void revokeIdTokens(String idToken) throws InterruptedException, E
 
 // [START save_revocation_in_db]
 DatabaseReferenceref = FirebaseDatabase.getInstance().getReference("metadata/" + uid);
-ref.setValueAsync(newHashMap<String, Object>().put("revokeTime", revocationSecond)).get();
+Map<String, Object> userData = newHashMap<>();
+userData.put("revokeTime", revocationSecond);
+ref.setValueAsync(userData).get();
 // [END save_revocation_in_db]
 
  }