Show background images in Dashboard Settings is not translated

[btlechowski]

Follow up to #7947.
Show background images is not translated

Steps to Reproduce

1. Clean profile
2. Open Brave in German(DE) locale
3. Open Dashboard Settings on NTP

Actual result:

Show background images in Dashboard Settings is not translated

Expected result:

Show background images in Dashboard Settings is translated

Reproduces how often:

Easily reproduced

Brave version (brave://version info)

Brave	1.15.56 Chromium: 85.0.4183.102 (Official Build) dev (64-bit)
Revision	ffe848af6a5df4fa127e2929331116b7f9f1cb30-refs/branch-heads/4183@{#1770}
OS	Ubuntu 18.04 LTS

Brave	1.16.19 Chromium: 86.0.4240.30 (Official Build) nightly (64-bit)
Revision	09f50eb5535879364cf00e72653462a509ef6bdc-refs/branch-heads/4240@{#552}
OS	Ubuntu 18.04 LTS

cc @brave/legacy_qa @rebron @mkarolin

[btlechowski]

Verification passed on

Brave	1.17.32 Chromium: 86.0.4240.80 (Official Build) nightly (64-bit)
Revision	7ed88b53bda45a2d19efb4f8706dd6b6cad0d3af-refs/branch-heads/4240@{#1183}
OS	Ubuntu 18.04 LTS

Verified test plan from the description

German locale:

Polish locale:

---

Verification passed on

Brave | 1.17.39 Chromium: 86.0.4240.99 (Offizieller Build) nightly (64-Bit)
-- | --
Überarbeitung | 002668237e13d38aabd6d11c2d216dd22b736ff2-refs/branch-heads/4240@{#1229}
Betriebssystem | Windows 10 OS Version 1903 (Build 18362.1082)

• Verified test plan from the description

German locale:

Hindi locale

Kannada locale

---

Verification PASSED on macOS 10.15.7 x64 using the following build:

Brave | 1.17.42 Chromium: 86.0.4240.99 (Official Build) nightly (x86_64)
-- | --
Revision | 002668237e13d38aabd6d11c2d216dd22b736ff2-refs/branch-heads/4240@{#1229}
OS | macOS Version 10.15.7 (Build 19H2)
JavaScript | V8 8.6.395.13

German	Chinese	Japanese