Add keyguard_config_prop for keyguard property

keyguard.no_require_sim becomes keyguard_config_prop to remove
exported*_default_prop

Bug: 155844385
Test: boot and see no denials
Change-Id: Icffa88b650a1d35d8c1cd29f89daf0644a79ddd3
diff --git a/private/platform_app.te b/private/platform_app.te
index ba6de5b..8163d15 100644
--- a/private/platform_app.te
+++ b/private/platform_app.te
@@ -87,6 +87,9 @@
 # allow platform apps to connect to the property service
 set_prop(platform_app, test_boot_reason_prop)
 
+# allow platform apps to read keyguard.no_require_sim
+get_prop(platform_app, keyguard_config_prop)
+
 # allow platform apps to create symbolic link
 allow platform_app app_data_file:lnk_file create_file_perms;