Fix NPE on non-distict multitouch device

Change-Id: I6d8a05bf62e510d0556fa4831b3d510041cca63a

java/src/com/android/inputmethod/keyboard/PointerTracker.java

@@ -459,6 +459,7 @@ public class PointerTracker {
                         keyboard.updateSpacebarPreviewIcon(diff);
                         // Display spacebar slide language switcher.
                         showKeyPreview(keyIndex);
+                        if (queue != null)
                             queue.releaseAllPointersExcept(this, eventTime, true);
                     }
                 }
@@ -551,6 +552,7 @@ public class PointerTracker {
 
     public void onLongPressed(PointerTrackerQueue queue) {
         mKeyAlreadyProcessed = true;
+        if (queue != null)
             queue.remove(this);
     }