Create a flag for SCM improvements for CD

The current intended usage of the flag is to make sure that SCM
apps won't get restared when moved between displays, but there
may be other ideas that will pop up down the road, so the name
of the flag is intentionally a bit more generic.

Flag: EXEMPT adding flag
Bug: 399752440
Test: m
Change-Id: Icc115dd9391cc0196dc0e9acc3d851b87ea46452