Disable Android AutoFill Implementation
In 8856a3c1, Mozilla added support for Fenix acting as an AutoFill service provider. The implementation isn't dangerous, but I assume it interacts in a surprising way with Tor Browser's disk avoidance goal - especially because I think the password manager implementation is currently broken for similar reasons.
Let's disable this until we can successfully support it. The current implementation is only enabled in Fenix Nightly and Debug (therefore it's not included in any Tor Browser).