Store transaction id in MdnsPacket

The transaction id is a number that is used to identify a
specific query packet. But it's not necessary for probing
or announcing services, so the transaction id is not
currently used on advertising when creating a MdnsPacket or
decoding the response to a MdnsPacket. This means that it is not
possible to track which query packets have received
responses. Therefore, store the transaction id so that
it can be used for subsequent query packet changes.

Bug: 302269599
Test: atest FrameworksNetTests
Change-Id: I6734752b32b91678afb7df06e1fa51237cf70894