Turn off synthetic VSYNC when adjusting thread scheduling for performance

* This CL explicitly sets synthetic VSYNC state based on the new power state. Before, the synthetic VSYNC state was assumed based on the previous power state and in some cases was not set explicitly.
* The previous behaviour of enabling synthetic VSYNC if the only display is DOZE_SUSPEND is preserved.
* This also fixes a hypothetical gap where it would not optimise for performance if there were a display that needed it, while the primary display was DOZE_SUSPEND.

Bug: 342681202

Bug: 241285876

Flag: android.companion.virtualdevice.flags.correct_virtual_display_power_state

Test: manually tested with flag on/off using Android Auto Projected

Change-Id: I181aefad586ad7b1732c837b67a01d61939d1d3e