Changes:

• Create the billable usage remittance in database in a single transaction
• Do not send the billable usage message to the topic platform.rhsm-subscriptions.billable-usage

Testing:

• After doing these changes, it's expected that some IQE tests start failing (because we're not sending the billable usage message anylonger), to fix these tests and verify these changes, we need to hit the endpoint created in SWATCH-3239