Fix potential NPE in MainKeyboardView.KeyTimerHandler

Bug: 8469652
Change-Id: Ib7a548e6a24d2e02de85ab444c0ec99d8f6b82c3
diff --git a/java/src/com/android/inputmethod/keyboard/MainKeyboardView.java b/java/src/com/android/inputmethod/keyboard/MainKeyboardView.java
index f0ca9c1..745e7df 100644
--- a/java/src/com/android/inputmethod/keyboard/MainKeyboardView.java
+++ b/java/src/com/android/inputmethod/keyboard/MainKeyboardView.java
@@ -229,6 +229,9 @@
         @Override
         public void handleMessage(final Message msg) {
             final MainKeyboardView keyboardView = getOuterInstance();
+            if (keyboardView == null) {
+                return;
+            }
             final PointerTracker tracker = (PointerTracker) msg.obj;
             switch (msg.what) {
             case MSG_TYPING_STATE_EXPIRED: