[$] Graphene OS: a security-enhanced Android build

People tend to put a lot of trust into their phones. Those devices haveaccess to no end of sensitive data about our lives - our movements,finances, communications, and more - so phones belonging to even relativelylow-profile people can be high-value targets. Android devices run freesoftware, at least at some levels, so it should be possible to ensure thatthey are working in their owners' interests. Off-the-shelf Androidinstallations tend to fall short of that goal. The GrapheneOS Android rebuild is an attemptto improve on that situation.