Remove Preconditions usage from moduleutils and IpClient

moduleutils is a shared utility to be used by multiple network modules.
Stop depending on a framework private class usage. Then all of its users
can stop depending on the statically linked and jarjared private
framework class.

Bug: 148636687
Test: atest TetheringTests NetworkStackNextTests
Change-Id: I693d0318fa4f1afbc220aa7c43e614ab5714a984