The DevicePolicyManagerService currently supports delegation of
certificate installation and application restriction management, both
of which are individually handled by DPMS.
Upcoming framework features will add four more delegation types,
namely: block uninstall; app permission management; app access
management; and system app enabler. At this moment it makes sense to
refactor the underlying delegation system in DPMS so that current and
future delegates can be handled in a more generic way.
Bug: 33099995
Test: DPMS unit tests
Change-Id: I9e350143572c6690febdd59d1ed5149af8ee4388
f994677626