Adding vendor_apex_file for /vendor/apex

apexd needs to read /vendor/apex dir and files in it.

Bug: 131190070
Bug: 123378252
Test: 1. Add apex to /vendor/apex
      -> see if boot succeeds with new policy
      2. Add flattened apex to /vendor/apex
      -> see if only root files are labelled as vendor_apex_file

Change-Id: I37795ab6d659ac82639ba5e34d628fe1b5cdb350
diff --git a/private/file_contexts b/private/file_contexts
index 4f0690b..9e7bba7 100644
--- a/private/file_contexts
+++ b/private/file_contexts
@@ -352,6 +352,8 @@
 /(vendor|system/vendor)/overlay(/.*)?          u:object_r:vendor_overlay_file:s0
 /(vendor|system/vendor)/framework(/.*)?        u:object_r:vendor_framework_file:s0
 
+/vendor/apex(/[^/]+){0,2}                      u:object_r:vendor_apex_file:s0
+
 # HAL location
 /(vendor|system/vendor)/lib(64)?/hw            u:object_r:vendor_hal_file:s0