Add waiter for secret_key in orders api tests

The secret creation process is asynchronous and secret_ref
is not present in order when created. The patch adds waiter for this
filed with predefined timeouts.

Related-Prod: PRODX-12928
Change-Id: I5f2369c49e4a19d0d00803f0396241b3056f0c67

Related-Prod: PRODX-22696
Change-Id: Ie8a303ee6d51c863406d86ae4eb9127cd1efae38
1 file changed