Removing TaskFragment token from LaunchActivityItem

The token was needed because the TaskFragment info may not
sent to the organizer before activity created.

The token is no longer necessary because the TaskFragment
info is now ensured to be updated before activity created.

Bug: 200303250
Test: wm presubmit
Change-Id: I69a42fa35efde4fc7f37ab50334de5de146da90d