Rare answer changes in Fioi_swpen_vdf and Fioi_swpen_vdr in branch run with CICE in prescribed mode

This is emerging from https://github.com/ESMCI/cime/issues/4911; see that issue for some context.

The summary is that, with a recent change in the definition of the ERI test, CAM is seeing a failure in the test `ERI_D_Ln18.ne16pg3_ne16pg3_mt232.FHIST_C4.derecho_intel.cam-outfrq3s_eri`, and it appears that this is due to an answer change within CICE (run in prescribed mode) in the branch run.

An ERI test runs the following cases:
- (1) Startup
- (2) Hybrid from restart files written in (1)
- (3a) Branch from restart files written in (2)
- (3b) Restart from restart files written in (3a)

It then compares:
- (3a) with (2) - to verify that a branch run doesn't change answers
- (3b) with (3a) - to verify that a restart doesn't change answers

The hybrid run changes the start year (to verify that the system works when changing the start year in a hybrid case). Until recently, the start year was changed by 2 years; the recent change to the ERI test is that the start year is now changed by 4 years. With this change, the comparison between (3a) and (2) is failing in this one ERI test, indicating that there is an answer change in the branch case relative to the case it's branching from.

The answer change appears in just two fields: `iceImp_Fioi_swpen_vdf` and `iceImp_Fioi_swpen_vdr`. (It looks like these fields are sent from ice to ocn, so it makes sense that, in this F compset, we're not seeing any feedbacks to the rest of the system.) In both cases, the difference is in a single grid cell, index 13627, where the hybrid case (2) has a non-zero value but the branch case (3a) has a zero value.

Before the recent change, case (2) started in year 1981; after the recent change, case (2) starts in year 1983. So it appears that there is a rare problem with non-bit-for-bit behavior of branch runs in CICE run in prescribed mode, which is triggered when branching from a case in early 1983 but not when doing an analogous branch from a case in early 1981.

FYI - @dabail10 @cacraigucar @fischer-ncar