Temporarily disable NsdService unit tests

The unit tests cannot pass before a newer prebuilt of Tethering is used,
as bootclasspath classes that it tests would be outdated.

This change is not merged in downstreams that build from source (changes
in the merged-in tags are not related changes, however).

Bug: 234099453
Test: atest

Merged-In: Ib1d180cc799dde94ada642ce752623b4b65f1e31
Merged-In: I44dda14cae265e600010c6f8efe1471ac481c6ea
Merged-In: I702a75e91be0bb582f9cbd7b4a23e1286f8252cf
Change-Id: I5b0cb131fcb5feb6b3cfd70e95ba7c5e54fa2294