Fix dot & badge being on correct side for the first bubble added

* stackAnimationController#isStackOnLeftSide depends on the position
  being set which happens when a view gets added so we should add
  the view & then set mStackOnLeftOrWillBe
* removed unused code

Test: manual 1) have no bubbles
             2) add a bubble (needs to be on left side -- this is
                the default unless you've placed the stack on right
                side beforehand)
             => observe that the update dot & badge are on the right
                hand side of the bubble
Bug: 185438888
Change-Id: I6129aff7c352fad8d29a6c243549f0d3580d62c8