Grammar fixes for database comments. (#2248)

Author: rlazo

firebase-database/src/main/java/com/google/firebase/database/Query.java

@@ -163,8 +163,8 @@ public ChildEventListener addChildEventListener(@NonNull ChildEventListener list
   }
 
   /**
-   * Get the server value for this query, updating cache and raising events if successful. If not
-   * connected, fall back to a locally-cached value.
+   * Gets the server values for this query. Updates the cache and raises events if successful. If not
+   * connected, falls back to a locally-cached value.
    */
   @NonNull
   public Task<DataSnapshot> get() {