Fix that bookmarks couldn't be added to .pro files with mouse

The area with the marks was not showing up.
This patch reverses the logic for showing the marks area to opt-out.
Almost all editors were opting in for it already. The AndroidManifest
editor, VCS base editor, and widget designer text editor opt out now.

Task-number: QTCREATORBUG-20339
Change-Id: Iccb6d0256618f7ef70e8921847ce2fd46fd660c0
Reviewed-by: David Schulz <david.schulz@qt.io>

src/plugins/android/javaeditor.cpp

@@ -75,7 +75,6 @@ JavaEditorFactory::JavaEditorFactory()
     setUseGenericHighlighter(true);
     setCommentDefinition(Utils::CommentDefinition::CppStyle);
     setEditorActionHandlers(TextEditor::TextEditorActionHandler::UnCommentSelection);
-    setMarksVisible(true);
     setCompletionAssistProvider(new TextEditor::KeywordsCompletionAssistProvider(keywords));
 }