WindowManager: Move mGlobalScale application to WindowState

As part of the overall thrust to remove WindowState we move the
application of the so called "GlobalScale" to the WindowState level of
the hierarchy. The remaining matrix code code in WSA will be cleaned up
in a follow-up CL, but we are landing this step immediately to unblock
BLAST which would otherwise be fighting with WSA to set the scale on
the WSA SurfaceControl

Bug: 161937501
Bug: 171956715
Bug: 168506246
Test: Existing tests pass. Repro from bug with BLAST enabled.
Change-Id: I2e0b2619ce3625f1089bf8a9411a31afb959b35c