Add default label and mapping for vendor services

Adding the default label/mapping is important because:
1.  Lookups of services without an selinux label should generate
    a denial.
2.  In permissive mode, lookups of a service without a label should be
    be allowed, without the default label service manager disallows
    access.
3.  We can neverallow use of the default label.

Bug: 37762790
Test: Build and flash policy onto Marlin with unlabeled vendor services.
    Add/find of unlabeled vendor services generate a denial.

Change-Id: I66531deedc3f9b79616f5d0681c87ed66aca5b80
(cherry picked from commit 639a2b84)

public/domain.te

@@ -421,18 +421,13 @@ neverallow * {fs_type -contextmount_type}:filesystem relabelto;
 neverallow { domain -recovery } contextmount_type:dir_file_class_set
     { create write setattr relabelfrom relabelto append unlink link rename };
 
-# Do not allow service_manager add for default_android_service.
+# Do not allow service_manager add for default service labels.
 # Instead domains should use a more specific type such as
 # system_app_service rather than the generic type.
-# New service_types are defined in service.te and new mappings
-# from service name to service_type are defined in service_contexts.
+# New service_types are defined in {,hw,vnd}service.te and new mappings
+# from service name to service_type are defined in {,hw,vnd}service_contexts.
 neverallow * default_android_service:service_manager add;
-
-# Do not allow hwservice_manager add for default_android_hwservice.
-# Instead domains should use a more specific type such as
-# hal_audio_hwservice rather than the generic type.
-# New service_types are defined in hwservice.te and new mappings
-# from service name to service_type are defined in hwservice_contexts.
+neverallow * default_android_vndservice:service_manager { add find };
 neverallow * default_android_hwservice:hwservice_manager { add find };
 
 # Looking up the base class/interface of all HwBinder services is a bad idea.

public/vndservice.te

+type default_android_vndservice, vndservice_manager_type;

vendor/vndservice_contexts

+*                       u:object_r:default_android_vndservice:s0