QS: Inversion tile: Don't consider initial 0 setting trackable.

For usage tracking purposes, seeing a setting value of 1 is always
considered trackable.

However, only consider a setting value of 0 as trackable if we've
observed a change (from 1).  Avoids tracking a db update from null
to 0 (via settings cmd or a restore).

Bug: 18062541
Change-Id: Ic8413b1770040f9ef28041bbadb4e5fb62d1c014