[SettingsLib] Extract attributes for entity header into styles

To enable device manufacturers to customize the settings header in ways
such as changing the orientation of the icon and title we need to have
the attributes taken out of they layout file and into a style so that
resource overlays can be used to customize those values.

Flag: NONE only xml files changed, cannot flag.
Test: Add these styles to PermissionController's overlayable and use
example overlay.
Bug: 344908070

Change-Id: I443a58103bec06dfe2a9176673ffe75c0c8b235a