Expose some testAPIs in DPM

Exposed the following testAPIs in DevicePolicyManager:
* getDefaultCrossProfilePackages
* getDisallowedSystemApps

Test: confirmed the APIs are callable in CTS tests
Bug: 180500227
Change-Id: I75a9a479920f1ba2c71f0c9b7e0148f90f1832ec
2 files changed