init: expand generated attributes on sepolicy compile

Expand auto generated attributes in selinux policy when doing
on-device compile of platform + vendor selinux policy.

Bug: 3650825
Test: Build and boot Marlin
Change-Id: Icc1c3af0b504236ae13fd8a5155c2109befd7688
diff --git a/init/init.cpp b/init/init.cpp
index 94bf37a..9b8f286 100644
--- a/init/init.cpp
+++ b/init/init.cpp
@@ -794,7 +794,7 @@
     const char* compile_args[] = {
         "/system/bin/secilc",
         plat_policy_cil_file,
-        "-M", "true",
+        "-M", "true", "-G",
         // Target the highest policy language version supported by the kernel
         "-c", std::to_string(max_policy_version).c_str(),
         "/system/etc/selinux/mapping_sepolicy.cil",