Checking success of injectInputEvent

Bug: 156287114
Change-Id: Id000b39a187c909475dd6dd409d14430b3654517
diff --git a/tests/tapl/com/android/launcher3/tapl/LauncherInstrumentation.java b/tests/tapl/com/android/launcher3/tapl/LauncherInstrumentation.java
index 79008a7..7c2d8a7 100644
--- a/tests/tapl/com/android/launcher3/tapl/LauncherInstrumentation.java
+++ b/tests/tapl/com/android/launcher3/tapl/LauncherInstrumentation.java
@@ -1144,7 +1144,8 @@
         }
 
         final MotionEvent event = getMotionEvent(downTime, currentTime, action, point.x, point.y);
-        mInstrumentation.getUiAutomation().injectInputEvent(event, true);
+        assertTrue("injectInputEvent failed",
+                mInstrumentation.getUiAutomation().injectInputEvent(event, true));
         event.recycle();
     }