Mark shell as system_executes_vendor_violators.

Bug: 62041836
Test: sailfish sepolicy builds

Change-Id: Iad865fea852ab134dd848688e8870bc71f99788d

public/shell.te

@@ -186,6 +186,8 @@ allow shell service_contexts_file:file r_file_perms;
 allow shell sepolicy_file:file r_file_perms;
 
 # Allow shell to start up vendor shell
+# TODO(b/62041836): system processes should not run vendor executables.
+typeattribute shell system_executes_vendor_violators;
 allow shell vendor_shell_exec:file rx_file_perms;
 
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