You can, but it's probably better that you don't
It tends to be the case that medication is discouraged because of the risks of allergies - Aspirin and NSAIDs like Ibuprofen, for example, can cause severe reactions in some people.
Savlon does have some allergy warnings ( see https://www.medicines.org.uk/emc/product/6330/smpc ) so this would be a potential risk, and if you were to treat someone with it and trigger an allergic reaction then it might be grounds for a lawsuit (NB: I am not a lawyer).
There is some information on recommended contents for a first aid kit here: https://fitforwork.org/blog/first-aid-kits-in-the-workplace-bs-8599-1/. Burn creams are not included in this list, but they do offer this advice on other items:
Workplace first aid kits can be complemented by other items that have been identified during a risk assessment, if necessary
So I would suggest that the need for burn cream would depend on the work environment.
Notably, the first question on that article concerns burn gels and the response states that they aren't normally necessary for treating burns except in rare circumstances such as chemical burns. It also links to the NHS advice for burns which is simply running water and clingfilm, and actually advises against creams ( https://www.nhs.uk/conditions/burns-and-scalds/treatment/ )