Add a stylus controller to Bluetooth Device Details.

In this CL stylus preferences will show for every type of input device.
Feature is currently flagged behing SETTINGS_SHOW_STYLUS_PREFERENCES.

Bug: b/251201006
Test: SettingsRoboTests StylusDevicesControllerTest
DD: go/stylus-connected-devices-doc
Change-Id: I73cec8e5cfd0b70be0492841f9d8e07f62a70863