Apply new remote animation when reusing existing activities

When reusing existing activity to a start activity flow. The new remote
animation wrapped in the start options might be ignored. Update to make
sure reusing existing activity will apply new remote animation. Also
makes sure to clear the next app transition after executed event it
throws.

Bug: 241191055
Test: atest ActivityStarterTests
Test: manual verified the new remote animation will be applied when
      reusing existing activity.
Change-Id: I0e3fc0ac0c349b0988222cc536e2bd88543871c8