Add a public test method to reset package version

Instead of having the cached version field protected, which is only
usable by DeviceConfigUtilsTest, have a public method to reset it to -1
so that other tests exercising feature flags can reset it before and
after running.

Bug: 173068192
Test: atest NetworkStaticLibTests
Change-Id: I8f5be3c91b2a47070507d5bf263e2e5d7d9d9d14
2 files changed
tree: e82771d2afd9b3bb8f2f040c37e9ae9c0812848f
  1. staticlibs/