Mark method @UsedForTesting

This prevents it from being optimized away.

Change-Id: Iecd317568e23e86e4c0ece8134a4926a7a56d65b

java/src/com/android/inputmethod/latin/utils/ExecutorUtils.java

@@ -101,6 +101,7 @@ public class ExecutorUtils {
             mRunnables = runnables;
         }
 
+        @UsedForTesting
         public Runnable[] getRunnables() {
             return mRunnables;
         }