In onKeyUp for DPAD_CENTER, show the IME for text input.

Fixes http://b/issue?id=2201966

Change-Id: Ifa8ab30e205e21e9e69e9a7405a0a6fc86c6c488

core/java/android/webkit/WebView.java

@@ -3410,6 +3410,7 @@ public class WebView extends AbsoluteLayout
             }
             if (isTextInput) {
                 rebuildWebTextView();
+                displaySoftKeyboard(true);
             }
             return true;
         }