Created attachment 1423671 [details]
Shows 500 error on source subscription allocation

Description of problem:
Using RHSM (which in turn is calling CP), while transferring entitlements of certain SKUs from a SAM 1.4 to SAM 1.2, the migration of entitlements fails with a 500 (which is an error returned directly from CP). Entitlements, however, are still removed from the source subscription allocation.
We also use Candlepin to migrate subscriptions between Satellites, so we wanted to make sure the flow when a failure occurs is as expected.

Version-Release number of selected component (if applicable):
RHSM 14.5.10 - RHSM 14.5.12

How reproducible:
Always

Steps to Reproduce:
Visit access.stage.redhat/management

Log-in with the following credentials:
tyjang2001/redhat

Visit https://access.stage.redhat.com/management/subscription_allocations/2f873d2e-4de3-48cc-a117-a848f42f0a00/subscriptions
In Search bar - Type "SER0135US"
Click check box next to Subscription and then hit "Move to Another Allocation"
Enter '10' in 'Quantity to Move'
Click "Next"
Select "SAM_1_2"
Click "Submit"

Actual results:
You get a 500 error but you'll see the entitlements decremented by 10
However, if you visit:
https://access.stage.redhat.com/management/subscription_allocations
You will see that "SAM_1_2" still has 0 Entitlements

Expected results:
We expect to get an error, but the entitlements on the source subscription
allocation should not be decremented since the transfer is not completed

Additional info:
Screenshots added