Hello, we are currently using Firefox ESR 60. I want to change the application used for PDF files like you can do under your settings, but with a policies.json file (described here https://support.mozilla.org/en-US/kb/use-adobe-reader-view-pdf-files-firefox). For the policies.json file i could only find the setting to disable the PDF viewer from firefox, but not to set it to another application. Is there any way to achieve this within a policies file or are there alternatives to configure this companywide without ADMX files? Thanks :)