Try to use broadcast for su logging and notify

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

native/jni/include/daemon.h

@@ -17,7 +17,7 @@ enum {
 	BOOT_COMPLETE,
 	MAGISKHIDE,
 	SQLITE_CMD,
-	ZYGOTE_NOTIFY,
+	BROADCAST_ACK,
 };
 
 // Return codes for daemon
@@ -82,6 +82,8 @@ void magiskhide_handler(int client);
  *************/
 
 void su_daemon_handler(int client, struct ucred *credential);
+void broadcast_test();
 
 extern int SDK_INT;
 extern bool RECOVERY_MODE;
+extern bool CONNECT_BROADCAST;