This simple Bedrock Behavior Pack helps me to understand Minecraft Bedrock Edition's Scripting/Behavior System. It will stop Creepers from Exploding even if Mob-Griefing is turned on.
Note: While I was developing I noticed that you can't do that with scripts. So I did it with the creeper.json.
Mob-Griefing turnes of the Griefing for every Mob... This Pack doesn't. 😉 A creeper will still explode when he gets lit with a flint and steel.