Decode the token before printing to output (#4342)

Fixes #4340

Co-authored-by: Takashi Matsuo <[email protected]>

Author: wwuck

endpoints/bookstore-grpc/jwt_token_gen.py

@@ -68,4 +68,4 @@ def generate_jwt(service_account_file, issuer, audiences):
     args = parser.parse_args()
 
     signed_jwt = generate_jwt(args.file, args.issuer, args.audiences)
-    print(signed_jwt)
+    print(signed_jwt.decode('utf-8'))