Set apex. property as "system_restricted"

Since the property is supposed to be used by vendor-side .rc file as
read-only (especially by vendor apex), it should be "system_restricted".

Also allow vendor_init to read the property.

Bug: 232172382
Test: boot cuttlefish (with vendor apex using the property)
Change-Id: I502388e550e0a3c961a51af2e2cf11335a45b992
diff --git a/private/property.te b/private/property.te
index 90db686..27a8e38 100644
--- a/private/property.te
+++ b/private/property.te
@@ -47,7 +47,6 @@
 system_internal_prop(ctl_odsign_prop)
 system_internal_prop(virtualizationservice_prop)
 system_internal_prop(ctl_apex_load_prop)
-system_internal_prop(apex_ready_prop)
 
 # Properties which can't be written outside system
 system_restricted_prop(device_config_virtualization_framework_native_prop)
@@ -655,6 +654,7 @@
   -coredomain
   -dumpstate
   -apexd
+  -vendor_init
 } apex_ready_prop:file no_rw_file_perms;
 
 neverallow {