Add sepolicy for KeyMint VM system properties exposed to vendors

Bug: 368502791
Test: launch_cvd --secure_hals=guest_keymint_trusty_insecure
Test: atest VtsAidlSharedSecretTargetTest
Change-Id: Ic07fcd01e4d27c2a666acbb6d24a157841ac6eff
diff --git a/private/property.te b/private/property.te
index 3694666..0f5a3f0 100644
--- a/private/property.te
+++ b/private/property.te
@@ -96,6 +96,11 @@
     system_restricted_prop(profcollectd_etr_prop)
 ')
 
+# These types will be public starting at board api 202504
+until_board_api(202504, `
+    system_vendor_config_prop(trusty_security_vm_sys_vendor_prop)
+')
+
 # Properties which should only be written by vendor_init
 system_vendor_config_prop(avf_virtualizationservice_prop)
 system_vendor_config_prop(high_barometer_quality_prop)