Inconsistency of todo keyword faces when faces defined as local variables

@alphapapa, As I described in [org-sidebar](https://github.com/alphapapa/org-sidebar/issues/42#issue-774966505), file-local keyword faces cannot be rightly displayed in org-sidebar. Though this is a org-sidebar issue, org-ql takes care of the codes as you mentioned, I file the issue here and will close [#42](https://github.com/alphapapa/org-sidebar/issues/42#issue-774966505).

As I offered there, the following small example would reproduce the problem. This is a small problem with no urgency, so please have a look if you have free time. Thanks again for coding all those awesome packages.

```org
#+TITLE:TODO keyword face problems

* TODO task 1

** TODO a child task
SCHEDULED: <2020-12-27 Sun>

** TODO another child task
SCHEDULED: <2020-12-28 Mon>

* NEXT Task 2
SCHEDULED: <2020-12-29 Tue>

* DONE Task 3
DEADLINE: <2020-12-30 Wed>

#+TODO: TODO(t) NEXT(n) | DONE(d)
# Local Variables:
# org-todo-keyword-faces: (("todo" . "red") ("NEXT" . "pink") ("DONE" . "green"))
# End:

```