Add owner field to android.hardware.tests.extension.vibrator

This will prevent the interface from being updated with aidl-freeze-api.
As the interface is for testing purpose, we really don't need to keep
the latest ToT version and the latest stable version to be the same.
Exempt that by adding the owner field to the interface.

Bug: 188713899
Test: m

Change-Id: I9a670f763c8f31f7c847f8ba8d4706efa075285e