Allow a --user param for cmd media.camera commands.

This allows testing on secondary users. For more information, please see go/aae-cts-on-u10

bug: 126472822
Test: Create and switch to secondary user.
$ cts-tradefed run cts -a arm64-v8a -m CtsCameraTestCases -t android.hardware.camera2.cts.IdleUidTest

and ...
$ adb install testcases/CtsCameraTestCases.apk
Success
$ adb shell cmd media.camera get-uid-state android.camera.cts --user 10
idle
$ adb shell cmd media.camera set-uid-state android.camera.cts active --user 10
$ adb shell cmd media.camera get-uid-state android.camera.cts --user 10
active
$ adb shell cmd media.camera get-uid-state android.camera.cts --user 0
idle
$ adb shell cmd media.camera get-uid-state android.camera.cts
idle
$ adb shell cmd media.camera reset-uid-state android.camera.cts --user 10
$ adb shell cmd media.camera get-uid-state android.camera.cts
idle
$ adb shell cmd media.camera get-uid-state android.camera.cts --user 10
idle

Change-Id: I7a5a3455d36ce6b95638ff13313f06e7e9b92feb