property_contexts: add cache for getDisplayInfo.

Test: getDisplayInfo works
Bug: 140788621
Change-Id: I131b9b34b9d2814ab2b2f95e5cef3635a67765e2
diff --git a/public/property_contexts b/public/property_contexts
index bdc862d..4b7c744 100644
--- a/public/property_contexts
+++ b/public/property_contexts
@@ -454,3 +454,4 @@
 cache_key.is_power_save_mode             u:object_r:binder_cache_system_server_prop:s0
 cache_key.is_user_unlocked               u:object_r:binder_cache_system_server_prop:s0
 cache_key.volume_list                    u:object_r:binder_cache_system_server_prop:s0
+cache_key.display_info                   u:object_r:binder_cache_system_server_prop:s0