Refactor apex data file types.

We ended up with 4 labels for specific APEX files that were all
identical; I've replaced them with a single one
(apex_system_server_data_file).

Additionally I created an attribute to be applied to a "standard" APEX
module data file type that establishes the basics (it can be managed
by vold_prepare_subdirs and apexd), to make it easier to add new such
types - which I'm about to do.

Fix: 189415223
Test: Presubmits
Change-Id: I4406f6680aa8aa0e38afddb2f3ba75f8bfbb8c3c
diff --git a/private/vold_prepare_subdirs.te b/private/vold_prepare_subdirs.te
index 956e94e..ad7e6bb 100644
--- a/private/vold_prepare_subdirs.te
+++ b/private/vold_prepare_subdirs.te
@@ -16,13 +16,9 @@
   vendor_data_file
 }:dir { open read write add_name remove_name rmdir relabelfrom };
 allow vold_prepare_subdirs {
-    apex_appsearch_data_file
-    apex_art_data_file
+    apex_data_file_type
     apex_module_data_file
-    apex_permission_data_file
     apex_rollback_data_file
-    apex_scheduling_data_file
-    apex_wifi_data_file
     backup_data_file
     face_vendor_data_file
     fingerprint_vendor_data_file
@@ -33,14 +29,10 @@
     vold_data_file
 }:dir { create_dir_perms relabelto };
 allow vold_prepare_subdirs {
-    apex_appsearch_data_file
-    apex_art_data_file
+    apex_data_file_type
     apex_art_staging_data_file
     apex_module_data_file
-    apex_permission_data_file
     apex_rollback_data_file
-    apex_scheduling_data_file
-    apex_wifi_data_file
     backup_data_file
     face_vendor_data_file
     fingerprint_vendor_data_file