Revert "fix system_server dex2oat exec"

This reverts commit 10370f5f.

The underlying issue has been fixed and the system_server
will now go via installd to get stuff compiled, if required.

bug: 16317188

Change-Id: I77a07748a39341f7082fb9fc9792c4139c90516d

system_server.te

@@ -14,7 +14,6 @@ allow system_server system_server_tmpfs:file execute;
 
 # For art.
 allow system_server dalvikcache_data_file:file execute;
-allow system_server dex2oat_exec:file rx_file_perms;
 
 # /data/resource-cache
 allow system_server resourcecache_data_file:file r_file_perms;