init: Run restorecon_recursive asynchronously

restorecon_recursive may take a long time if there are a lot of files on
the volume.  This can trigger a watchdog timeout in any process that
tries to set a property while it is running.  Fix this by running
restorecon_recursive in its own process.

See https://jira.lineageos.org/browse/BUGBASH-555

Change-Id: I2ce26ff2b5bfc9a133ea42f4dbac50a3ac289c04
diff --git a/init/service.cpp b/init/service.cpp
index 1a6474b..b73ddfb 100644
--- a/init/service.cpp
+++ b/init/service.cpp
@@ -1085,6 +1085,8 @@
     } else if (pid == -1) {
         PLOG(ERROR) << "waitpid failed";
         return false;
+    } else if (PropertyChildReap(pid)) {
+        return true;
     }
 
     Service* svc = FindServiceByPid(pid);