Merge pull request #41557 from AkihiroSuda/cherrypick-41156-1903

[19.03 backport] dockerd-rootless.sh: support new containerd shim socket path convention

contrib/dockerd-rootless.sh

@@ -88,6 +88,6 @@ else
 	[ $_DOCKERD_ROOTLESS_CHILD = 1 ]
 	# remove the symlinks for the existing files in the parent namespace if any,
 	# so that we can create our own files in our mount namespace.
-	rm -f /run/docker /run/xtables.lock
+	rm -f /run/docker /run/containerd /run/xtables.lock
 	exec dockerd $@
 fi