Fix AppCompatSpinner not overlaying the IME

Caused by ListPopupWindow using an internal version of
PopupWindow.getMaxAvailableHeight() which allows ignoring
of window decorations. We now use that method via reflection.

BUG: 23387567
Change-Id: I753090f58d7c74b588b15bea2a6fb09b8ed1c58d
1 file changed