sepolicy: add rules for bionic.linker.16kb.app_compat.enabled

This property serves as the global toggle for 16kb app compat.

It must be world readable since the linker is executed in the context
of the process requesting the dynamic linking.

Currently, only init and root shell are allowed to set the property.
This may be modified later to also allow toggling from the settings
app.

Bug: 339709616
Test: m
Change-Id: Ie0fd4132477460d88c3cf2f09aa59084f54cfea7
Signed-off-by: Kalesh Singh <kaleshsingh@google.com>
diff --git a/private/property.te b/private/property.te
index 1f94608..7c2d6d1 100644
--- a/private/property.te
+++ b/private/property.te
@@ -71,6 +71,7 @@
 
 
 # Properties which can't be written outside system
+system_restricted_prop(bionic_linker_16kb_app_compat_prop)
 system_restricted_prop(device_config_virtualization_framework_native_prop)
 system_restricted_prop(fstype_prop)
 system_restricted_prop(log_file_logger_prop)
@@ -834,3 +835,9 @@
   -init
   -vendor_init
 } pm_archiving_enabled_prop:property_service set;
+
+neverallow {
+  domain
+  -init
+  userdebug_or_eng(`-su')
+} bionic_linker_16kb_app_compat_prop:property_service set;