[MINOR] clean up style for storage param setters in ALS

Clean up style for param setter methods in ALS to match standard style and the other setter in class (this is an artefact of one of my previous PRs that wasn't cleaned up).

## How was this patch tested?
Existing tests - no functionality change.

Author: Nick Pentreath <nickp@za.ibm.com>

Closes #13480 from MLnick/als-param-minor-cleanup.