Restart failed system calls interrupted with errno of EINTR

In number of places we don't handle properly system calls failures
when the errno is EINTR (i.e., the system call was interrupted
by a signal). In all our use cases, the system calls should be
restarted. The handling of the following system calls (as used in the code)
has been updated/fixed:

  poll, send, recv, sendmsg, nanosleep, epoll_wait
  read - mostly (e.g., socket-like fds)
  write - mostly (e.g., socket-like fds)
  select, accept, connect

Bug: 28471477
Bug: 28658141
Change-Id: I03e6f0f67e33876780fb6d02c33eb84547ba8f95