Fix a couple issues with sysui state

- Ensure that we only set the sysui state on the default display for the
  time being since gesture nav only really works for the default display
- Update the overview proxy service of the nav bar fragment window state
  whenever it is recreated
- Remove the screen pinning flag usage as there is no callback to
  accurately ensure that this flag is always up to date (launcher will
  have to use the activity manager call whenever it needs to check
  it for now)

Bug: 131552865
Test: Manual

Change-Id: I524f67f4fb6eb73e6e07454d9eb0c03d3ffb53af