Add flag checks for DPM API calls

Check for the flag enabled status for EnforcingAdmin.getComponentName()
and DPM.EXTRA_ENFORCING_ADMIN API calls.

Test: None.
Bug: 414733570
Flag: android.app.admin.flags.enforcing_admin_get_component_name_enabled
Flag: android.app.admin.flags.enforcing_admin_extra_enabled

Change-Id: Ia161a9fbe2a99efe82ed45e4d28412fc02b48b40