persist.sysui.notification.ranking_update_ashmem

Adds persist.syui.notification.ranking_update_ashmem property and
associated permissions, which will be used to flag guard a change in
core/...NotificationRankingUpdate.java.

Permissions are limited in scope to avoid unnecessary access.
Apps may need to read the flag (because NotificationRankingUpdate.java
is a core library), but setting should only be possible internally (and
via debug shell).

Test: manual flash+adb setprop/getprop
Bug: 249848655
Change-Id: I661644893714661d8c8b5553c943fa17d08c000c
diff --git a/private/property.te b/private/property.te
index 35f9bc7..66c9cea 100644
--- a/private/property.te
+++ b/private/property.te
@@ -55,6 +55,7 @@
 system_restricted_prop(device_config_virtualization_framework_native_prop)
 system_restricted_prop(log_file_logger_prop)
 system_restricted_prop(persist_sysui_builder_extras_prop)
+system_restricted_prop(persist_sysui_ranking_update_prop)
 
 ###
 ### Neverallow rules