Make the new setSecondaryLockscreen a SystemApi

Removed the ComponentName parameter since this can only be used by the
SYSTEM_SUPERVISION role holder.

Test: m
Bug: 356895431
Bug: 361098832
Flag: android.app.admin.flags.secondary_lockscreen_api_enabled

Change-Id: I9a11eaf053dd5ecff28c0add6b282472bb91b168
3 files changed