Increase xinetd connections for rsync

- Increase connections to 512 with 10 second rate
- Set per_source to UNLIMITED
- Specify IPv4 flag

Change-Id: Ia007301eca8e006e9792c73d0d35350588c48b96
Closes-bug: 1330495
Closes-bug: 1322577
Merge "Increase xinetd connections for rsync"