Fix invalidateOutline

Bug: 18175261

invalidateOutline was switched to a lazy-method, but this doesn't
work because invalidateViewProperty intentionally does not
do a traversal, therefore the invalidate was never consumed.

However it was attempting to be lazy about work that is cheap to
do, so nuke the lazy aspect and restore invalidateOutline's previous,
correct behavior. rebuildOutline is kept to avoid triggering
traversals in places they are not needed

Change-Id: I70f8cbacd54a607c0bf0bc7fe6eea78554cb2ea3