Disable "Verify apps over usb" according to user restriction.

This is ag/2124876 which fails to automerge oc-dev->master, so
sending as a separate change. Will add Merged-In to the original CL
before submitting to oc-dev.

Bug: 37158436
Test: make ROBOTEST_FILTER=VerifyAppsOverUsbPreferenceControllerTest RunSettingsRoboTests
Change-Id: I52d40f4176ecd660c621ec056649c94fc29f2d4b