Brave News error message needs translated strings

[stephendonner]

Description

Steps to Reproduce

1. set your OS system language to Japanese
2. launch Brave, open a new tab, and enable Brave Today
3. either somehow force or encounter an error condition (disconnect from Wi-Fi, intercept request, etc.) to force the error page
4. look at the error-page text

Actual result:

Error page text is in English, stating "Brave Today is experiencing some issues. Try again."

Expected result:

Error-page text should be in Kanji.

Reproduces how often:

100% (once you hit this error condition, that is)

Brave version (brave://version info)

Brave	1.23.21 Chromium: 89.0.4389.72 (Official Build) nightly （x86_64）
変更履歴	3f345f156bfd157bd1bea06310e55f3fb2490359-refs/branch-heads/4389@{#1393}
OS	macOS バージョン11.2.2（ビルド20D80）

Version/Channel Information:

• Can you reproduce this issue with the current release? n/a
• Can you reproduce this issue with the beta channel? n/a
• Can you reproduce this issue with the nightly channel? yes