Give FloatingIconView a copy of, rather than, the original icon.

Previously, if a user tapped on the clock icon then rapidly swiped back,
the clock icon would stop updating. This fixes that issue by avoiding
changes to the original icon's inner callback state while preparing and
displaying the FloatingIconView.

Bug: 188377749
Test: Locally enabled the second hand on the clock icon in addition to
the minute and hour hands, then verified that it was incrementing
correctly every second even after tapping then rapidly swiping back on
the clock icon.

Change-Id: Ib8eddb53de293194e5f9dce2fcafe8a481a6116c