Can temporary filler be used to hide/smooth out possible granuloma bumps in my upper lip? (Photos)

I would go to a board certified plastic surgeon to have this assessed and to talk about your options. The problem with silicone injections is that there is a risk of a complication if filler is injected around these substances. When the silicone sets sometimes it encapsulates itself and if a substance is injected around these granulomas it can make the granulomas grow more as the silicone reacts. Or there is a potential to get an infection more easily. 

You need to have this assessed in person by a really qualified injector such as a board certified plastic surgeon or cosmetic dermatologist. Silicone and fillers don't always play well together and the filler may have made the bumps from the silicone worse. 

Granulomas following silicon injections were quite common and many patients suffer their consequences. There is not a single treatment that works in all cases. The most common are serial injections of steroids at higher doses than one would use in  granulomas caused by absorbable fillers.
Sometimes a combination of steroid injections with systemic steroids and immunosuppressive agents are necessary. You will eventually respond to one of the above but you must be patient; treatment may take months.
As a rule, avoid any filler that contains any amount of  non-absorbable, non-retrievable and non-dissolvable particles.