[Sb refactor] Move WifiRepositoryImpl to prod/ package

Note that this CL modifies the ktfmt_includes so we can keep the
WifiRepositoryImplTest rename from running ktfmt, which would break the
blame history.

Test: existing tests
Bug: 238425913
Change-Id: I9c6b9ba3905728c31859cac1d6703be4d77f3db0