Customize text on NTP is not translated

[btlechowski]

Follow up to #4930

Steps to Reproduce

1. Openn NTP in Polish locale

Actual result:

Customize is not translated
The tooltip is not translated

Expected result:

Customize is translated
The tooltip is translated

Reproduces how often:

100% repro rate

Brave version (brave://version info)

Reproduced on

Brave	1.8.72 Chromium: 81.0.4044.92 (Official Build) dev (64-bit)
Revision	e98e6f21168a55e7ba57202f56323911cd9d31d1-refs/branch-heads/4044@{#883}
OS	Ubuntu 18.04 LTS

Reproduced on

Brave	1.9.18 Chromium: 81.0.4044.92 (Official Build) nightly (64-bit)
Revision	32921c79b6f01a0fb2deef0e1d45b42f96581051-refs/branch-heads/4044@{#883}
OS	Ubuntu 18.04 LTS

cc @mkarolin @rebron @brave/legacy_qa @cezaraugusto

[elemanhillary-zz]

i would like to be assigned this

[mkarolin]

The string was added via brave/brave-core#5103 after we did the latest l10n round (brave/brave-core#5089). If it's important to have this localized sooner than the next round (for 1.9.x) then pls let me know.

[elemanhillary-zz]

@mkarolin yes it is.

[bsclifton]

@elemanhillary you can sign up for our Transifex project here:
https://www.transifex.com/brave/brave/

This is where we pull the translations from 😄 Anything other than English on GitHub gets destroyed and replaced with the contents of Transifex when we pull latest

[GeetaSarvadnya]

Verification passed on

Brave	1.8.84 Chromium: 81.0.4044.122 (Official Build) (64-bit)
Revision	44f4233f08910d83b146130c1938256a2e05b136-refs/branch-heads/4044@{#963}
OS	Windows 10 OS Version 1803 (Build 17134.1006)

• Verified the test plan from the description
  

Verified passed with

Brave	1.8.84 Chromium: 81.0.4044.122 (Official Build) (64-bit)
Revision	44f4233f08910d83b146130c1938256a2e05b136-refs/branch-heads/4044@{#963}
OS	macOS Wersja 10.14.6 (kompilacja 18G3020)

• Verified STR from description
  

Verification passed on

Brave	1.8.85 Chromium: 81.0.4044.122 (Official Build) (64-bit)
Revision	44f4233f08910d83b146130c1938256a2e05b136-refs/branch-heads/4044@{#963}
OS	Ubuntu 18.04 LTS