dynamic_sensor: Use HID unique ID for head tracker UUID.

Also, don't require 16-bit strings for HID name, manufacturer, and
unique ID. Also change dump of HID unique ID to be in hex.

Bug: 213483369
Test: Verified that the standard Android head tracker sensor uses the
 HID unique ID for the sensor UUID.
Test: Verified that custom Android sensors use a fabricated UUID.
Change-Id: I125f84187868543dccab758e22dce744c013578e
2 files changed