Make one-handed bouncer properly inhibit falsing.

Previously, the falsing manager would take all taps that weren't on the
bouncer (ish) as potential false taps, eventually dismissing the
bouncer. This causes issues for the one-handed bouncer; taps on the
"other" side were registered as false taps, so in many cases, tapping to
move the bouncer would cause the falsing to kick in.

To fix, this CL inhibits falsing for gestures that begin on the
"opposite" bouncer side.

This also refactors a bunch of the code to decide whether to use a one
handed bouncer, to move a lot of logic into the ContainerController. The
animations on change, and tap to change are still handled in the View,
but the decision of whether to enter one-handed mode, and which side to
open on, are now handled in the Controller.

FYI - this CL still attempts to load from settings; that will be cleaned
up in a follow-up CL.

Bug: 182982037
Bug: 170858298
Test: Tests updated and pass.
Change-Id: Icb36a3b88032c4bcad8530d518a97a8d8717244e