Rename the binder cache key for hasSystemFeature()

The code that uses the property has not been committed, so this change
has no impact on the codebase.

Bug: 140788621

Test: build an image that combines this change with the client code
and boot a phone.  Verify that there are no policy violations.

Change-Id: Ie6c1a791578c61adae5b71a38e61a2f5b20bb817
diff --git a/public/property_contexts b/public/property_contexts
index 8397b85..6d0826b 100644
--- a/public/property_contexts
+++ b/public/property_contexts
@@ -441,6 +441,6 @@
 ro.surface_flinger.refresh_rate_switching u:object_r:exported_default_prop:s0 exact bool
 
 # Binder cache properties.  These are world-readable
-binder.cache_key.has_system_feature      u:object_r:binder_cache_system_server_prop:s0
+cache_key.has_system_feature             u:object_r:binder_cache_system_server_prop:s0
 cache_key.is_interactive                 u:object_r:binder_cache_system_server_prop:s0
 cache_key.is_power_save_mode             u:object_r:binder_cache_system_server_prop:s0