Refine the naming about compatible scale

There can be 2 reasons that we need to apply compatible scale to a
window:

1. The app doesn't support large screen. We would layout the window as
   if it is on a small display. And then we need to scale its window up
   to match the display.

2. We put a running app into a container that the size doesn't fit. We
   need to down-scale the app so that it can fit the container.

The scaling of case 2 is also known as size-compat-scale which is fully
controlled at the server side. The client shouldn't know about it. And
this CL refines the naming.

Fix: 258393096
Bug: 254187021
Test: presubmit
Change-Id: Ifbd2ca725bed231d9e6dd8190df3dc773d4402b7