Previously, processes which used file-system Unix Domain Sockets could not be
checkpoint-ed in runsc because the sockets were saved with their inode
numbers which do not necessarily remain the same upon restore. Now,
the sockets are also saved with their paths so that the new inodes
can be determined for the sockets based on these paths after restoring.
Tests for cases with UDS use are included. Test cleanup to come.
PiperOrigin-RevId: 208268781
Change-Id: Ieaa5d5d9a64914ca105cae199fd8492710b1d7ec
4ececd8e8d