uwb: Add owners for uwb service

The code changes are in internal branch in topic:
https://googleplex-android-review.git.corp.google.com/q/topic:uwb_aosp_service

Only pulling in the OWNERS changes to AOSP.

Bug: 183904955
Test: N/A
Change-Id: I035e908e32090415c6f0e9071084c360abf5aee7