Avoid going over max service name length when renaming NSD services

As per  RFC 1034/1035, the max size of the label is 63 bytes. It should
also be guaranteed when the serviceName is renamed due to the conflict.

Bug: 265865456
Test: atest FrameworksNetTests
Change-Id: I077d8abdb91071db62b9618d9918e3a12682aaf4
6 files changed