Fix put_encrypted_blob function (Azure#15918)

Fixing function by setting key_encryption_key instead of  key_resolver_function

sdk/storage/azure-storage-blob/samples/blob_samples_client_side_encryption.py

@@ -142,7 +142,7 @@ def put_encrypted_blob(self):
             # this property will tell the service to encrypt the blob. Blob encryption
             # is supported only for uploading whole blobs and only at the time of creation.
             kek = KeyWrapper('key1')
-            self.container_client.key_resolver_function = kek
+            self.container_client.key_encryption_key = kek
 
             self.container_client.upload_blob(block_blob_name, u'ABC', )