Update record receipt time on records updated

The receipt time in the MdnsResponse need to be updated every time new
packet is received. And then the record refreshing logic could calculate
remaining TTL correctly.

Original change: https://r.android.com/2614892

Change-Id: I4fea296496c2bd3e988601079513365b35a52ad8
Fixes: 285260665
Test: atest CtsNetTest FrameworksNetTests
Merged-In: Ib7a290ea0ea8e552c71c657696397e8114fcee52
6 files changed