Assume virtual devices always have USB connection.

We use the presence of an active USB data connection to suppress
the RescueParty logic.  For example, all physical devices in a test
lab return "true" here to avoid interfering with test results.

Since virtual devices are pretty much only used in test labs, return
true for them too.

Bug: 37347800
Test: builds, boots
Change-Id: Ie79ce57ce67fb78234c1001a593918253a85254d