Fix NPE on HOVER_EXIT event when not touching a key.

Bug: 6513368
Change-Id: Ia6d4d01f51a620230b4d19f813fb3aff6881ec03
diff --git a/java/src/com/android/inputmethod/accessibility/AccessibleKeyboardViewProxy.java b/java/src/com/android/inputmethod/accessibility/AccessibleKeyboardViewProxy.java
index 1b0e488..2623dcc 100644
--- a/java/src/com/android/inputmethod/accessibility/AccessibleKeyboardViewProxy.java
+++ b/java/src/com/android/inputmethod/accessibility/AccessibleKeyboardViewProxy.java
@@ -113,7 +113,7 @@
         case MotionEvent.ACTION_HOVER_EXIT:
             // Make sure we're not getting an EXIT event because the user slid
             // off the keyboard area, then force a key press.
-            if (pointInView(x, y)) {
+            if (pointInView(x, y) && (key != null)) {
                 getAccessibilityNodeProvider().simulateKeyPress(key);
             }
             //$FALL-THROUGH$