Fix DisplayCutout.{width,height} units

This CL fixes the unit of DisplayCutout.{width,height}, which I forgot
to change at the same time as the bounds units in ag/34831624.

Bug: 417960167
Test: Manual, verified the dimensions in Flexiglass shade
Flag: com.android.systemui.scene_container
Change-Id: I63d138ba2c877976b0557fa7a1dc98339b84b2cb