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/system_server.te b/private/system_server.te
index 4356c26..d30f657 100644
--- a/private/system_server.te
+++ b/private/system_server.te
@@ -842,6 +842,8 @@
 
 # Read persist.sysui.notification.builder_extras_override property
 get_prop(system_server, persist_sysui_builder_extras_prop)
+# Read persist.sysui.notification.ranking_update_ashmem property
+get_prop(system_server, persist_sysui_ranking_update_prop)
 
 # Read ro.tuner.lazyhal
 get_prop(system_server, tuner_config_prop)