Title: Refactor outlier detection config message fields

Description:
As discussed in #8130 (comment), the outlier detection configuration fields are a bit messy and could use a cleanup. The main work here is to de-dup all of the options into a common message around enabled, local origin split, etc. and then hopefully just have a single field per actual ejection type. This would avoid an explosion of almost identical fields for each different ejection type.