Move some display logic into hierarchy [2/2]

Move display update logic from WM into ATM hierarchy by letting
ActivityStack watch for relevant changes and calculate bounds
accordingly and removing configuration updates from WM side
outside of calls from the display-level controller (like how
the other levels work).

One of the main display-changes to account for is rotation. To
make this work without drastically modifying things was to leave
display freeze/startSeamless in WM but move the actual rotation
to ATM while handling SEND_NEW_CONFIGURATION. This prevents
changes to the wm-side hierarchy outside of ATMS's control.

To facilitate this extra communication between ATMS and WM,
this adds rotation into WindowConfiguration. This makes rotation
available to the hierarchy update for policies that care about it
(things like split). It will also replace TaskStack's mRotation
in an upcoming CL and should also let us remove the one-off
variable for landscape->seascape orientation changes (needs
some more research though).

Bug: 113900640
Test: go/wm-smoke + relevant am/wm servicestests
Change-Id: I12c79cc5eb94d48d846f1cf27765c9f9f6741435