Change sleep image to echo image

Author: J12934

operator/config/samples/Dockerfile

@@ -1,2 +1,2 @@
 FROM alpine
-ENTRYPOINT [sleep, 5s]
+ENTRYPOINT ["echo"]

operator/config/samples/execution_v1_readandwritehook.yaml

@@ -1,8 +1,8 @@
 apiVersion: execution.experimental.securecodebox.io/v1
 kind: ScanCompletionHook
 metadata:
-  name: "sleep-rw"
+  name: "echo-rw"
 spec:
-  image: "sleep"
+  image: "echo"
   type: "ReadAndWrite"
   env: []