GZDoom folder is not created on first launch of the app

[mkrupczak3]

#Tested on Nougat API 25

Description:
It appears that the app attempts to create a GZdoom directory and config sub-directory before properly acquiring storage permissions from the user. Even after giving it permissions, the folder will not be created properly until the app is re-launched.

Steps to reproduce:
On first launch after the user taps "Allow" on the permissions request and navigates to the options fragment and taps the "RESET" button for the GZDoom folder a message appears saying "/storage/emulated/0/GZDoom is not a directory

Ideas to fix:
Have the app attempt to create the GZdoom directory directly after acquiring permissions (if it does not already exist)
Have the app attempt to create the GZdoom directory upon navigating to options fragment (if it does not already exist)
Have the app attempt to create the GZdoom directory upon navigating to any fragment (if it does not already exist)