KeyguardManager: Fix user resolution of isDeviceSecure/Locked

Fixes isDeviceSecure and isDeviceLocked APIs to use
the user id of the app that executes the code rather
than that of any incoming binder call.

Change-Id: Ib7772b60c35a3ebf96830f9b013c539021e1f063
Fixes: 34592592
Test: manual