Add falsing to quick settings buttons.

Quicksettings buttons will now reject single taps that either don't
look like clean single taps or that fail other single-tap falsing
criteria.

However, with this change we also allow clean double taps to be
recognized as single taps for the purposes of falsing. If a single
tap fails, a double tap might work.

Bug: 172655679
Test: atest SystemUITests && manual
Change-Id: Icab57e98e2784f3c152b4496db8fc97c2235cbec