UsbDeviceManager: Adapt for data signaling quirks

Always treat USB as disconnected if USB data signaling is turned off.
Set USB functions to none, and send a state change event.

The resulting behavior matches the Google Pixel series, which already
reports USB as disconnected when data signaling is turned off, but the
Motorola series (and maybe others that use Qualcomm's HAL) do not.

Test: Manual: Set Restrict USB to Always allow. Connect to a computer.
Observe the USB notification on device. Set Restrict USB to Deny. Check
that the notification disappears. Search Settings for USB and tap the
Connected devices > USB result. The "Use USB for" section is disabled.

Issue: calyxos#2154
Change-Id: I9d8753d4dbb18012e0d40f4991ab4c15bad14de1