To be done after SERVER-79317. We should replace isEnabledAndIgnoreFCVUnsafeAtStartup with isEnabledUseLatestFCVWhenUninitialized since isEnabledUseLatestFCVWhenUninitialized is more accurate (for example, a binary 7.0 with 6.0 FCV, and a feature flag that is enabled on 7.0. While FCV is uninitialized during initial sync, both isEnabledAndIgnoreFCVUnsafeAtStartup and isEnabledUseLatestFCVWhenUninitialized would return true, but once the FCV is correctly set to 6.0, then isEnabledAndIgnoreFCVUnsafeAtStartup would still return true, while isEnabledUseLatestFCVWhenUninitialized would correctly return false, which is more correct since once the FCV is initialized to 6.0, that feature flag should return false for isEnabled).

However, as part of this we should audit the use cases of isEnabledAndIgnoreFCVUnsafeAtStartup just to make sure changing them to isEnabledUseLatestFCVWhenUninitialized is correct.