Remove Preconditions usage to stop dependecy with non-updatble class

Stop depending on Preconditions that is not released on the same cadence
as the module, and is maintained as part of the framework.

Bug: 148636687
Test: atest TetheringTests NetworkStackNextTests

Merged-In: Id0dcec44f362f79bc8c046d722635687a7388aa2
Change-Id: Id0dcec44f362f79bc8c046d722635687a7388aa2