[SettingsLib] fix test after IPackageManager flag change

ag/16288469 changed some of IPackageManager methods to use long flags
instead of int flags. That CL didn't include a fix for Settings Lib
tests. This CL fixes that.

BUG: 208469125
Test: atest com.android.settingslib.users.AppRestrictionsHelperTest
Change-Id: I0c2a7db2844baf84d382fdbdc5ce88ffe360a173