Include descriptor in Binder token for AppPredictor

Adding a descriptor in Binder token can help us identifying potential
binder proxy leaks in the future.

This CL also made the Binder token static. Binder token serves as an
indicator of the termination of a process, there's no reason in making
multiple Binder token since when the process dies, they all dies.

Bug: 240329370
Test: manual
Change-Id: I26969395d704aa6518ef9d834951f856d74924b7