AutoComplete list does not hide the IME when it re-appears.

Bug 3415891

With the current behavior, as soon as the list is expanded by
'long' pressing on or scrolling its content, it will always further appear
in its long state, thus hiding the IME.

This fix changes this behavior so that the default state is always
compact, not hiding the IME, and an explicit expansion
is always required.

Also fixes a bug in ListPopupWindow that prevented the timer that
expands the list from being started.

Change-Id: I896e92d54961769c10b276c36f6510e91ff096a2