Clear calling identity before calling into UserManagerService

For cases where the settings are being written synchronously from
an API call, make sure to clear the calling identity before
querying users to avoid a SecurityException.

Bug: 113105346
Test: atest CtsContentTestCases:PackageManagerTest
Change-Id: I28b78dce99d36caa58ab448476ec01a51689246b
1 file changed