Clearing binder identity before getting the current User

Otherwise it checks for Interact user permission which is not required for the locale change.

Flag: EXEMPT minor fix

Bug: 322229751
Test: atest --user-type secondary_user_on_secondary_display CtsCarTestCases:android.car.cts.LocaleManagerTest
Test: atest CtsCarTestCases:android.car.cts.LocaleManagerTest
Change-Id: I7a5b18a6caf49a5dc91043a59015d2360ad4e766