[CLI] Specifying 'Magma' as the storage backend on bucket creation should default bucket eviction policy to 'Full Eviction'

What needs to be done?
Right now when creating a bucket the bucket eviction policy defaults to 'Value Eviction' (--bucket-eviction-policy flag can be used to specify bucket eviction policy explicitly) for both Couchstore and Magma buckets (can be specified using --storage-backend flag).

As mentioned in MB-50704, the default eviction policy for Magma buckets is 'Full Eviction', which means that we need to make sure that whenever the type of a bucket is specified as 'Magma' (using --storage-backend flag) the bucket is created with bucket eviction policy set to 'Full Eviction' unless specified otherwise (using --bucket-eviction-policy flag).