Guard VirtualDevice#close by permission

If the permission is not already held by the caller through other means,
this causes unregistration failures, since the unique id disassociation
requires a signature permission. Clear the binding identity if the
permission is found, allowing use of the permisson. This is especially
important for CTS tests, and for access by non-signature apps.

Bug: 217275682
Test: atest CtsHardwareTestCases:android.hardware.input.cts.tests
Change-Id: Ide5232e5b5b5b1b3ca96e5cbfb997e4a1001a583