Dismiss resize frame before adding widget with add button

This change updates LauncherAccessibilityDelegate so that any open
widget resize frame is closed before searching for space on the
workspace. While the resize frame is open, its cells are marked
unoccupied, so LauncherAccessibilityDelegate may try to place something
in that space.

Bug: 374228746
Test: follow repro steps in bug
Flag: EXEMPT bug fix
Change-Id: Ibcd0711fff53182d91e9781a73f00c979c15e189