Setup a common channel to trunk stable flags in system properties

This is a common root node for native trunk stable flags in system properties. Each flag in a namespace will appear in the sys prop as

persist.device_config.trunk_stable_flags.<namespace>.<flag>

Bug: b/295379636
Change-Id: I42e4a799781a9ced442cbdcbdb6b905446d72d73
diff --git a/private/flags_health_check.te b/private/flags_health_check.te
index 9afaba0..ff47dec 100644
--- a/private/flags_health_check.te
+++ b/private/flags_health_check.te
@@ -25,6 +25,7 @@
 set_prop(flags_health_check, device_config_configuration_prop)
 set_prop(flags_health_check, device_config_connectivity_prop)
 set_prop(flags_health_check, device_config_surface_flinger_native_boot_prop)
+set_prop(flags_health_check, device_config_trunk_stable_flags_prop)
 set_prop(flags_health_check, device_config_vendor_system_native_prop)
 set_prop(flags_health_check, device_config_vendor_system_native_boot_prop)
 set_prop(flags_health_check, device_config_virtualization_framework_native_prop)