system_server: Report dalvikcache_data_file execute violations.

With build/core eaa9d88cf, system_server should not be loading code
from /data. Add an auditallow rule to report violations.

Bug: 37214733
Test: Boot marlin, no SELinux audit lines for system_server.
Change-Id: I2e25eb144503274025bd4fc9bb519555851f6521
(cherry picked from commit 665128fa)

private/system_server.te

@@ -18,6 +18,10 @@ allow system_server zygote_tmpfs:file read;
 # For art.
 allow system_server dalvikcache_data_file:dir r_dir_perms;
 allow system_server dalvikcache_data_file:file { r_file_perms execute };
+userdebug_or_eng(`
+  # Report dalvikcache_data_file:file execute violations.
+  auditallow system_server dalvikcache_data_file:file execute;
+')
 
 # /data/resource-cache
 allow system_server resourcecache_data_file:file r_file_perms;