API for setting the power state of a virtual device.

Equivalent to a "virtual power button". "Pressing" it will turn all
of the device's displays on/off, which will affect the relevant power
groups and virtual display states.

Only applied to trusted non-mirror displays, as they should be in the
default power group.

Bug: 285020111
Test: CTS
Flag: android.companion.virtualdevice.flags.device_aware_display_power
Change-Id: I083c48c5e773fb2f17f7bcea3df30a76aac65e97