Translation string loading order
When GravityView loads translations, it looks in the following locations, in the following order:
/wp-content/languages/plugins/gravityview-{locale}.mo
(loaded by WordPress Core)/wp-content/mu-plugins/gravityview-{locale}.mo
/wp-content/mu-plugins/languages/gravityview-{locale}.mo
/wp-content/plugins/gravityview/languages/gravityview-{locale}.mo
If you want to override translations, place them in any of the first three directories using that naming structure.