Fix leading spaces in kubectl commands

This is causing bash/zsh shells to not to record the executed command in the
history. See this link for details: https://unix.stackexchange.com/questions/115917/why-is-bash-not-storing-commands-that-start-with-spaces

Signed-off-by: Ahmet Alp Balkan <ahmetb@google.com>

docs/tasks/inject-data-application/distribute-credentials-secure.md

@@ -37,16 +37,16 @@ username and password:
 
 1. Create the Secret
 
-        kubectl create -f secret.yaml
+       kubectl create -f secret.yaml
 
     **Note:** If you want to skip the Base64 encoding step, you can create a Secret
     by using the `kubectl create secret` command:
 
-        kubectl create secret generic test-secret --from-literal=username='my-app' --from-literal=password='39528$vdg7Jb'
+       kubectl create secret generic test-secret --from-literal=username='my-app' --from-literal=password='39528$vdg7Jb'
 
 1. View information about the Secret:
 
-        kubectl get secret test-secret
+       kubectl get secret test-secret
 
     Output:
 
@@ -56,7 +56,7 @@ username and password:
 
 1. View more detailed information about the Secret:
 
-        kubectl describe secret test-secret
+       kubectl describe secret test-secret
 
     Output:
 
@@ -80,11 +80,11 @@ Here is a configuration file you can use to create a Pod:
 
 1. Create the Pod:
 
-        kubectl create -f secret-pod.yaml
+       kubectl create -f secret-pod.yaml
 
 1. Verify that your Pod is running:
 
-        kubectl get pod secret-test-pod
+       kubectl get pod secret-test-pod
 
     Output:
 
@@ -94,7 +94,7 @@ Here is a configuration file you can use to create a Pod:
 
 1. Get a shell into the Container that is running in your Pod:
 
-        kubectl exec -it secret-test-pod -- /bin/bash
+       kubectl exec -it secret-test-pod -- /bin/bash
 
 1. The secret data is exposed to the Container through a Volume mounted under
 `/etc/secret-volume`. In your shell, go to the directory where the secret data
@@ -127,11 +127,11 @@ Here is a configuration file you can use to create a Pod:
 
 1. Create the Pod:
 
-        kubectl create -f secret-envars-pod.yaml
+       kubectl create -f secret-envars-pod.yaml
 
 1. Verify that your Pod is running:
 
-        kubectl get pod secret-envars-test-pod
+       kubectl get pod secret-envars-test-pod
 
     Output:
 
@@ -140,7 +140,7 @@ Here is a configuration file you can use to create a Pod:
 
 1. Get a shell into the Container that is running in your Pod:
 
-        kubectl exec -it secret-envars-test-pod -- /bin/bash
+       kubectl exec -it secret-envars-test-pod -- /bin/bash
 
 1. In your shell, display the environment variables: