[TNU03] Add TetheringNotificationUpdaterTest

Add new test for TetheringNotificationUpdater

Bug: 122085773
Bug: 130596698
Test: atest TetheringTests
Change-Id: I0db3df3e85dd6a8c3989c8bc66a06c50f45a0c15
Merged-In: I0db3df3e85dd6a8c3989c8bc66a06c50f45a0c15
(cherry picked from aosp/1209985)
2 files changed