Make default permission checks in performance service more restrictive.

- Check sending process in unrestricted policies.
- Allow IsTrustedUid() to cache results for better runtime efficiency.
- Update tests to verify unrestricted policy behavior.

Bug: 62468109
Test: performance_service_tests passes.
Change-Id: I0614879c8bde35ffeda2f673a3da68092433dc1a
3 files changed