Can you tell me a bit more about the build type (development, shipping) and what you set the target SDK to? It should only be requesting permission if it is set to 23 or higher. Shipping can avoid needing external permission by setting the "“Use ExternalFilesDir for UE4Game files” checkbox in Android project settings.
I test build the UnrealMatch3 project with development build type, and the target SDK version is 23 cause 4.16 required which installed by CodeWorksforAndroid-1R6u1.
I don’t change any other setting for UnrealMatch3, and each time i open the game from S6,it is request to comfirm the permissions for accessing the photo,media and file.
In Android SDK project settings, SDK level should be “latest”, NDK level should be android-19. In Android Project Settings, set Min SDK to 13, and Target SDK to 19. This shouldn’t ask for permissions. Setting Target SDK to 23 will. We tested with Unreal Match 3 before release, but I’ll have QA try it again.