chore: Migrate gsutil usage to gcloud storage (#1631)

Author: bhandarivijay-png

appengine/flexible/ruby31-and-earlier/storage/README.md

@@ -17,7 +17,7 @@ project id with `gcloud config list`.
 Create a Cloud Storage bucket for your project:
 
 ```
-$ gsutil mb gs://<your-project-id>
+$ gcloud storage buckets create gs://<your-project-id>
 ```
 
 ## Run

appengine/flexible/storage/README.md

@@ -17,7 +17,7 @@ project id with `gcloud config list`.
 Create a Cloud Storage bucket for your project:
 
 ```
-$ gsutil mb gs://<your-project-id>
+$ gcloud storage buckets create gs://<your-project-id>
 ```
 
 ## Run

appengine/standard-storage/README.md

@@ -17,7 +17,7 @@ project id with `gcloud config list`.
 Create a Cloud Storage bucket for your project:
 
 ```
-$ gsutil mb gs://<your-project-id>
+$ gcloud storage buckets create gs://<your-project-id>
 ```
 
 ## Run

appengine/storage/README.md

@@ -17,7 +17,7 @@ project id with `gcloud config list`.
 Create a Cloud Storage bucket for your project:
 
 ```
-$ gsutil mb gs://<your-project-id>
+$ gcloud storage buckets create gs://<your-project-id>
 ```
 
 ## Run