Added support for creating always unlocked displays

Allows the holders of ACCESS_COMPUTER_CONTROL permission to be
able to create always unlocked displays. This will help in avoiding the
virtual displays executing the automated tasks to not pause when the
user locks out the device

Bug: 419461673
Test: Manually testing the CC agent app
Flag: android.companion.virtualdevice.flags.computer_control_access
Change-Id: I2301bc87c386c4123957b54a2df30abcb24da0d4