Fix merge conflict size limit

CHANGELOG

@@ -97,6 +97,7 @@ v 8.12.0 (unreleased)
 v 8.11.5 (unreleased)
   - Optimize branch lookups and force a repository reload for Repository#find_branch
   - Fix member expiration date picker after update
+  - Make merge conflict file size limit 200 KB, to match the docs
   - Fix suggested colors options for new labels in the admin area. !6138
   - Fix GitLab import button
   - Remove gitorious from import_sources

lib/gitlab/conflict/parser.rb

@@ -18,7 +18,7 @@ module Gitlab
 
       def parse(text, our_path:, their_path:, parent_file: nil)
         raise UnmergeableFile if text.blank? # Typically a binary file
-        raise UnmergeableFile if text.length > 102400
+        raise UnmergeableFile if text.length > 200.kilobytes
 
         begin
           text.to_json

spec/lib/gitlab/conflict/parser_spec.rb

@@ -179,8 +179,8 @@ CONFLICT
           to raise_error(Gitlab::Conflict::Parser::UnmergeableFile)
       end
 
-      it 'raises UnmergeableFile when the file is over 100 KB' do
-        expect { parse_text('a' * 102401) }.
+      it 'raises UnmergeableFile when the file is over 200 KB' do
+        expect { parse_text('a' * 204801) }.
           to raise_error(Gitlab::Conflict::Parser::UnmergeableFile)
       end