Fixed delete on android text fields

Text boxes delete characters in reaction to the backspace key down event, not the char event. On Android, the key down event was not being passed to the form. This is why only backspace wasn't working.

gameplay/src/PlatformAndroid.cpp

@@ -1028,7 +1028,7 @@ static int32_t engine_handle_input(struct android_app* app, AInputEvent* event)
         switch(action)
         {
             case AKEY_EVENT_ACTION_DOWN:
-                Game::getInstance()->keyEvent(Keyboard::KEY_PRESS, getKey(keycode, metastate));
+                gameplay::Platform::keyEventInternal(Keyboard::KEY_PRESS, getKey(keycode, metastate));
                 if (int character = getUnicode(keycode, metastate))
                     gameplay::Platform::keyEventInternal(Keyboard::KEY_CHAR, character);
                 break;