Add import and export options for history,bookmarks,passwords and rest of the browsing data to Firefox Android version

[Rudo55]

As the title says since the Desktop version has that i was wondering why it doesnt include it on android version of firefox since for those who prefer and not using Firefox Sync and to import or export browsing data locally and without and account which most desktop browsers has that so i would consider to add this on Android and also to include for those who want to transition from chromium to firefox based broswers as well.