change language is invalid

[Alanscut]

Change the language to chinese, but it does not take effect.

Kibana version:
v6.8.6-3

Elasticsearch version:
v6.8.6

Server OS version:
mac os 10.15.5

Browser version:
chrome 84.0.4147.105

Browser OS version:
mac os 10.15.5

Original install method (e.g. download page, yum, from source, etc.):
git clone https://github.com/chaoss/grimoirelab.git
run the project with docker-compose

Description of the problem including expected versus actual behavior:
when I change the language through kibana browser setting:

or change the language in kibana.yml:

when I restart the kibiter docker, the language of the browser is still english, but what i expect is chinese.

Steps to reproduce:

1. as mentioned above