Bypass IME for ListPopupWindowTest#testListSelectionWithDPad

Send KeyEvents directly to the InputMethodManager of the test app,
instead of relying on IME.

Changed KeyEventUtil to send null to dispatchKeyEventFromInputMethod.
Otherwise it couldn’t dispatch event to PopupWindows.

Bug: 28523261
Change-Id: I1a21efc50c9870bc599318f18d3d204f1350dc47
2 files changed