chore: fix get RPO sample (#1207)

* chore: fix get RPO sample

There was an extra line here that doesn't make sense. Fixing based
on external user feedback.

* Update samples/snippets/storage_get_rpo.py

Co-authored-by: cojenco <cathyo@google.com>

* remove constant import

---------

Co-authored-by: cojenco <cathyo@google.com>

samples/snippets/storage_get_rpo.py

@@ -25,7 +25,6 @@
 # [START storage_get_rpo]
 
 from google.cloud import storage
-from google.cloud.storage.constants import RPO_DEFAULT
 
 
 def get_rpo(bucket_name):
@@ -34,9 +33,7 @@ def get_rpo(bucket_name):
     # bucket_name = "my-bucket"
 
     storage_client = storage.Client()
-    bucket = storage_client.bucket(bucket_name)
-
-    bucket.rpo = RPO_DEFAULT
+    bucket = storage_client.get_bucket(bucket_name)
     rpo = bucket.rpo
 
     print(f"RPO for {bucket.name} is {rpo}.")