Add double-tap to quick resize desktop tasks

When the caption detects a double-tap gesture, it toggles that
task's size between the stable bounds or the default bounds,
depending on the current state.

Double-tap gesture detection relies on #onTouch calls that return
true for ACTION_DOWN events (because returning false causes the
listener to not receive subsequent ACTION_UP events due to
ACTION_DOWN being considered the starting point of the gesture). That
change however means that the ACTION_DOWN event is consumed and
breaks any OnClickListener from being called (e.g. the close and
caption menu buttons). For that reason, the click is now detected and
performed manually from #onTouch too.

Bug: 277275531
Test: double-tap on window header, verify it resizes between
the stable bounds and the default bounds.

Change-Id: I00214533179554301c22fac2d5a58626d84cb194