Only One Version of Discount with Active Model Versions for Cycle Forward is Applied (Doc ID 566157.1)

A discount with two active model versions for Monthly Cycle Forward events is only applied with one of the versions. The discount versions are configured so the first version is valid until May 1st with a 50% discount and the second starting on May 1st with a 30% discount (when the new discount is effective, the old one expires).

Example: when billing is applied for an account with DOM 10 for the cycle of April 10th to May 10th, there is only one discount version that is applied for the cycle forward fee. In this case, only the 50% discount is applied for the whole cycle in two generated events,
1. the first event charges from Apr 10 to May 01 (50% discount) and
2. the second from May 01 to May 10 (50% discount, but should be 30%)
both with 50%. Instead, the first event should get a 50% discount and the second event only 30%.

From May 10 - Jun 10, it is getting 30% discount. This is correct.

-- Steps To Reproduce:
1. Create a discount for cycle forward events. It is important that 2nd version starts in the
middle of the billing cycle, for example May 1st.
2. Create an account on April 10th, and assign a cycle forward product and its discount.
3. Run billing on May 10th.