Extract DisplayState elements into ScreenshotArgs

Only a subset of display state variables are needed for a screenshot
and can be passed around in the existing ScreenshotArgs struct. This
simplifies the parameter list passed around in screenshots and is a
step toward refactoring screenshots to be cleaner and separated into
a separate class.

Ideally, once everything is split into a separate class, SF will deal
with all the main thread work and provide the subset of screenshot
arguments that are need by the yet-to-come screenshotter class.

Bug: b/377758217
Test: atest SurfaceFlinger_test, atest CompositionTest
Test: presubmit, screenshots, screen lock/unlock
Flag: EXEMPT, refactor
Change-Id: Id66d108824b5fab6f110867f2b86408928dc7519