Fix clone() for Animators with just a 'to' value

Previously, clone() on an Animator with only one value would mistakenly
think that the clone had a real starting value (which would end up being 0 in the
int and float cases). Fix is to set the 'mHasFirstValue' flag appropriately for the
clone, based on the state of the cloned animator.

Issue #7106442 ObjectAnimator.clone() does not work properly for single parameter

Change-Id: I08bf03b7687a65eb613c1671a58e4cbfae66a30e