Set user root for trusty security VM

Bug: 431822422
Test: build and run  qemu_trusty_arm64-trunk_staging-userdebug target
Flag: EXEMPT only used in qemu
Change-Id: I2b22fac92ea82ba2541147e0b5afe3eebb803d33
diff --git a/guest/trusty/security_vm/launcher/security_vm_launcher-arm64.rc b/guest/trusty/security_vm/launcher/security_vm_launcher-arm64.rc
index 28a7493..ae15750 100644
--- a/guest/trusty/security_vm/launcher/security_vm_launcher-arm64.rc
+++ b/guest/trusty/security_vm/launcher/security_vm_launcher-arm64.rc
@@ -7,7 +7,8 @@
 --protected \
 --allow-ffa
     disabled
-    user system
+    # TODO(b/404820976): revert to `user system` when LSM hook solution is available
+    user root
     group system virtualmachine
     capabilities IPC_LOCK NET_BIND_SERVICE SYS_RESOURCE SYS_NICE IPC_OWNER
     stdio_to_kmsg