Merge pull request #23192 from orsenthil/docfixes/ubuntu_install

Fix the docker daemon restart command for ubuntu.

docs/installation/linux/ubuntulinux.md

@@ -391,7 +391,7 @@ To specify a DNS server for use by Docker:
 
 5. Restart the Docker daemon.
 
-        $ sudo restart docker
+        $ sudo service docker restart