Add missing aconfig container field to packages/modules/Virtualization

Bug: 330354107
Test: CI
Flag: NONE
Change-Id: I676184aa3b37a1b7ea51c3deca4062d9525e5526
diff --git a/avf_flags.aconfig b/avf_flags.aconfig
index 589d227..a5260a9 100644
--- a/avf_flags.aconfig
+++ b/avf_flags.aconfig
@@ -1,4 +1,5 @@
 package: "com.android.system.virtualmachine.flags"
+container: "com.android.virt"
 
 flag {
   name: "avf_v_test_apis"