Add an explicit user root for accessor_demo

Without an explicit user, this defaults to root.
This has become an error in Android 16, so this test started failing on
Cuttlefish when we bumped it to be an android 16 device.

Test: vm_accessor_test
Bug: 363085010
Change-Id: I605e3f1c0387cdfe6837973f22c164e2279e91bf
diff --git a/tests/vm_accessor/apex/accessor_demo.init.rc b/tests/vm_accessor/apex/accessor_demo.init.rc
index f3dfae9..1ebb038 100644
--- a/tests/vm_accessor/apex/accessor_demo.init.rc
+++ b/tests/vm_accessor/apex/accessor_demo.init.rc
@@ -16,5 +16,6 @@
 service accessor_demo /apex/com.android.virt.accessor_demo/bin/accessor_demo
     disabled
     oneshot
+    user root
     # MUST match with VINTF and accessor/src/main.rs
     interface aidl android.os.IAccessor/IAccessorVmService/default