In commit 8d4c407, native Magisk always launches an activity for
communicating with Magisk Manager. While this works extremely well,
since it also workaround stupid OEMs that blocks broadcasts, it has a
problem: launching an activity will claim the focus of the device,
which could be super annoying in some circumstances.
This commit adds a new feature to run a broadcast test on boot complete.
If Magisk Manager successfully receives the broadcast, it will toggle
a setting in magiskd so all future su loggings and notifies will always
use broadcasts instead of launching activities.
Fix#1412
Introduce a new communication method between Magisk and Magisk Manager.
Magisk used to hardcode classnames and send broadcast/start activities to
specific components. This new method makes no assumption of any class names,
so Magisk Manager can easily be fully obfuscated.
In addition, the new method connects Magisk and Magisk Manager with random
abstract Linux sockets instead of socket files in filesystems, bypassing
file system complexities (selinux, permissions and such)
