Update USB settings screen

Screen now handles data role and power
role switching as separate categories.

Change the UsbBackend api to use predefined
constants. Split out data and power direction
changes into separate functions.

Add tests for new controllers and new backend
functionality.

Bug: 72829348
Test: passes
Change-Id: I28b96cf49463fa4f3a4b6be41c57d5841731fbd6