Polish the .editorconfig file

Summary:
We should use indent size 2 everywhere. While we were using 4 for some old reasons. This is causing editing of .kts files and BUCK files inside OSS Android Studio quite painful.

Changelog:
[Internal] -

Reviewed By: cipolleschi

Differential Revision: D78348532

fbshipit-source-id: 97e0e1f54fdc76c8a9cdc44e1f67684c9e97a08f

Author: cortinico

.editorconfig

@@ -9,12 +9,3 @@ end_of_line = lf
 insert_final_newline = true
 indent_style = space
 indent_size = 2
-
-[*.gradle]
-indent_size = 4
-
-[*.kts]
-indent_size = 4
-
-[BUCK]
-indent_size = 4