Remove TaskInfo#topActivityToken usage in size compat for security

Security report shows that this can cause leak token of different app.

Replace the functionality with a callback to the TaskOrganizerController
to restart activity when size compat restart button is clicked.

Bug: 186776724
Test: manually verify the restart button still works
Change-Id: I097b9f02e8435e6765695b9d5a531a4e165bac66
Merged-In: I097b9f02e8435e6765695b9d5a531a4e165bac66