Correctly blame ANR on process using another process token

Activities can give their window tokens to other process to add
windows with. E.g. -1 screen on launcher. We were in correctly
blaming the process that gave out its token when an ANR occurs
because we were looking at the process associated with the activity.
This CL fixes that.

Test: manual
Change-Id: I08fca00d12ab89dc27eb104115fd375bb4e8ec66
Fixes: 36730136