init: V devices need to specify user

This also specifies user on an adbd service
declaration which was missing before. It seems
that certain services are declared mulitple
times.

Fixes: 276813155
Test: boot (on CF, the only V device in the tree)
Test: remove 'user' specification and see error

Change-Id: I138f3ace72d46f221551ad61e75ba4c01632da59