Add system property to disable avf remote attestation

Introduce a new system property
avf.remote_attestation.enabled to allow vendors
to disable the feature in vendor init.

Bug: 341598459
Test: enable/disable the feature and check VmAttestationTestApp
Change-Id: I809e4c62a8590822eef70093e33854ab79757835
diff --git a/private/virtualizationservice.te b/private/virtualizationservice.te
index b5c04af..f7db405 100644
--- a/private/virtualizationservice.te
+++ b/private/virtualizationservice.te
@@ -34,6 +34,10 @@
 # pVM remote attestation.
 hal_server_domain(virtualizationservice, hal_remotelyprovisionedcomponent_avf)
 
+# Allow the virtualizationservice to inspect whether remote attestation is supported
+# through the system property.
+get_prop(virtualizationservice, avf_virtualizationservice_prop)
+
 # Allow calling into the system server to find "permission_service".
 binder_call(virtualizationservice, system_server)
 allow virtualizationservice permission_service:service_manager find;