Give art_boot explicit access to experiment flags.

Test: SELinuxUncheckedDenialBootTest
Bug: 281850017
Change-Id: I2e05c3f9f390ee5d5302dbdaed72da0fa3dcc200
diff --git a/private/art_boot.te b/private/art_boot.te
index 1b088d6..0922931 100644
--- a/private/art_boot.te
+++ b/private/art_boot.te
@@ -4,6 +4,10 @@
 
 init_daemon_domain(art_boot)
 
+# Allow query of device config properties, typically experiment flags.
+get_prop(art_boot, device_config_runtime_native_boot_prop)
+get_prop(art_boot, device_config_runtime_native_prop)
+
 # Allow ART to set its config properties at boot, mainly to be able to propagate
 # experiment flags to properties that only may change at boot.
 set_prop(art_boot, dalvik_config_prop_type)