Fix an issue where we'd hide the IME while dragging collapsed bubbles

regressed in ag/31411312 -- fix is simple, check if we're expanded

Flag: EXEMPT trivial fix
Test: manual - focus IME in fullscreen app, drag bubbles
             => ensure IME remains up and bubbles can be dismissed
Fixes: 394507905
Change-Id: Id4df18a263da9ab687fe49376a4abc0561ca4c55