mantle: fix podman.workflow stop test

Sometime between podman 1.x and 2.x podman started putting
full 64 character IDs into the json output. Dynamically detect
the length of the ID and compare that number of characters.

We haven't noticed this test failing because we've been denylisting
the test in the pipeline: coreos#1478

mantle/kola/tests/podman/podman.go

@@ -140,7 +140,7 @@ func podmanWorkflow(c cluster.TestCluster) {
 
 		cmd = fmt.Sprintf("sudo podman run -d -p 80:80 -v %s/index.html:%s/index.html:z %s", string(dir), wwwRoot, image)
 		out := c.MustSSH(m, cmd)
-		id = string(out)[0:12]
+		id = string(out)[0:64]
 
 		podIsRunning := func() error {
 			b, err := c.SSH(m, `curl -f http://localhost 2>/dev/null`)
@@ -179,7 +179,10 @@ func podmanWorkflow(c cluster.TestCluster) {
 
 		found := false
 		for _, container := range psInfo.containers {
-			if container.ID == id {
+			// Sometime between podman 1.x and 2.x podman started putting
+			// full 64 character IDs into the json output. Dynamically detect
+			// the length of the ID and compare that number of characters.
+			if container.ID == id[0:len(container.ID)] {
 				found = true
 				if !strings.Contains(strings.ToLower(container.Status), "exited") {
 					c.Fatalf("Container %s was not stopped. Current status: %s", id, container.Status)