* Ensure that LongPress (LongClick) on Android properly uses touch slop
Previously, we assumed that multiple touch action events would occur
before a LongClick, but that is not necessarily true.
It is possible to just have one down touch immediately followed by a
LongClick, so we now account for that.
This also fixes the tracking of touch event locations such that
stale values aren't accidentally used when calculating if a finger movement
exceeded the allowable touch slop for considering a touch as a long press.
(Rust would've caught that... thanks Java)
* remove excess log stmt
* Fix modal event handling behavior
Everything now works as expected, *except* for Scroll events that seem to
still be received by views beneath the modal, e.g., an underlying PortalList.
* Enable widgets to block scrolling, except within a certain area
* This is important for Modals to prevent scrolling of background widgets
whilst still allowing the inner `content` view to be scrolled.
* Modals are now forcibly full-screen (or rather, full-window)
in order to properly ensure that scrolling-allowed areas
always stay relevant, as the Modal can no longer be contained
within a non-full-window parent widget/view.
* remove errant log statement
