Factor out adding records to a generic

- Make a method addOrReplaceRecord() that can support point,
  inet4Address and inet6Address records adding.
- Also fix some leftover comments in aosp/2431933

Bug: 268586836
Test: atest FrameworksNetTests
Change-Id: I01462a967a04e88f14dcbb92ca207deb4268612c
4 files changed