Permissions for odrefresh and /data/misc/apexdata/com.android.art

odrefresh is the process responsible for checking and creating ART
compilation artifacts that live in the ART APEX data
directory (/data/misc/apexdata/com.android.art).

There are two types of change here:

1) enabling odrefresh to run dex2oat and write updated boot class path
   and system server AOT artifacts into the ART APEX data directory.

2) enabling the zygote and assorted diagnostic tools to use the
   updated AOT artifacts.

odrefresh uses two file contexts: apex_art_data_file and
apex_art_staging_data_file. When odrefresh invokes dex2oat, the
generated files have the apex_art_staging_data_file label (which allows
writing). odrefresh then moves these files from the staging area to
their installation area and gives them the apex_art_data_file label.

Bug: 160683548
Test: adb root && adb shell /apex/com.android.art/bin/odrefresh
Change-Id: I9fa290e0c9c1b7b82be4dacb9f2f8cb8c11e4895
diff --git a/private/system_server.te b/private/system_server.te
index 12fb3fa..9f17021 100644
--- a/private/system_server.te
+++ b/private/system_server.te
@@ -32,8 +32,8 @@
 allowxperm system_server apk_data_file:file ioctl { INCFS_IOCTL_READ_SIGNATURE INCFS_IOCTL_FILL_BLOCKS INCFS_IOCTL_GET_FILLED_BLOCKS };
 
 # For art.
-allow system_server dalvikcache_data_file:dir r_dir_perms;
-allow system_server dalvikcache_data_file:file r_file_perms;
+allow system_server { apex_art_data_file dalvikcache_data_file }:dir r_dir_perms;
+allow system_server { apex_art_data_file dalvikcache_data_file }:file r_file_perms;
 
 # When running system server under --invoke-with, we'll try to load the boot image under the
 # system server domain, following links to the system partition.