Add user restriction to suppress error dialogs.

Bug: 66125576
Test: cts-tradefed run cts-dev --module DevicePolicyManager -t com.android.cts.devicepolicy.UserRestrictionsTest
Test: bit FrameworksServicesTests:com.android.server.pm.UserRestrictionsUtilsTest
Change-Id: I1c4cf4a107f47e9b5543607e57b76dd2e5acfba5