Allow dataloaders (priv_app) access to IncFs enabled property.

Bug: 179395351
Test: install an app incrementally using dev phonesky
Change-Id: I47496622ecef3f5552126a96d88cc0732cdf5dce
diff --git a/private/priv_app.te b/private/priv_app.te
index 9fd319f..4b0218e 100644
--- a/private/priv_app.te
+++ b/private/priv_app.te
@@ -170,6 +170,9 @@
 # on the Incremental File System.
 allowxperm priv_app incremental_control_file:file ioctl INCFS_IOCTL_PERMIT_FILL;
 
+# allow privileged apps to read the vendor property that indicates if Incremental File System is enabled
+get_prop(priv_app, incremental_prop)
+
 # Required for Phonesky to be able to read APEX files under /data/apex/active/.
 allow priv_app apex_data_file:dir search;
 allow priv_app staging_data_file:file r_file_perms;