As an admin
I want to be able to set the limit of file size at instance level
so that I can have a different limit for different instances.
Given a Liferay instance
When an admin sets a value for the limit of the instance
Then users won't be able to upload files to sites/asset libraries of that instance bigger than the limit set.
Given a Liferay instance and site A with a file size limit at system level
When an admin sets a value for max file size at instance level
Then the limit established at instance level takes precedence.