only allow dpad center for key long press

Holding down the enter key on a physical keyboard
doesn't make sense to map to long press; the desktop
doesn't work that way either.

bug:3344108
Change-Id: Icf02940dcadf194357b680ae1e3028751d16a1ea

core/java/android/webkit/WebView.java

@@ -4656,7 +4656,7 @@ public class WebView extends AbsoluteLayout
             return false;
         }
 
-        if (isEnterActionKey(keyCode)) {
+        if (keyCode == KeyEvent.KEYCODE_DPAD_CENTER) {
             switchOutDrawHistory();
             boolean wantsKeyEvents = nativeCursorNodePointer() == 0
                 || nativeCursorWantsKeyEvents();