Replace COMMON_CRITERIA_MODE setting with getter API

Per API review feedback, global settings are discouraged in favour
of fine-grained getter APIs.

Bug: 149999040
Test: atest com.android.cts.devicepolicy.MixedDeviceOwnerTest#testCommonCriteriaMode
Test: atest com.android.cts.devicepolicy.OrgOwnedProfileOwnerTest#testCommonCriteriaMode
Test: atest FrameworksServicesTests:DevicePolicyManagerTest
Change-Id: Ia810f67409ce2b482bca06f1e21df2f98d12ccfd