"Sodium azide reacts with heavy metals (such as silver, gold, lead, copper, brass, or solder in plumbing systems); and metal salts to form an accumulation of the highly explosive compounds such as lead azide and copper azide."
Assume reaction is fast. How many micromoles of gold/cm^2 constitute your film? How many micromoles of azide/volume are in your application? Will the gold be corroded through?
Is the gold there as a convenience or as a necessary surface? A brief soak in dilute decanethiol solution plus rinse will cover the surface with a monomolecular layer of hydrocarbon, each chain being anchored by its sulfur. The surface will be passivated and probably hydrophobic. 1-hydroxy-10-decanethiol will give a hydrophilic surface. Is it worth the bother and expense to diddle with the gold surface?
Gold is selling for $(USD)42.15/g today. How much gold is in your annual discard pile? When my school dumped a load of ancient undergrad combustion bombs I went through them. They originally shipped each with a platinum crucible. One remained. Half a Troy ounce of platinum was a good hour's tax-free wage.