White border is added to brave://welcome page

[GeetaSarvadnya]

Description

White border is added to brave://welcome page

Steps to Reproduce

1. Open 1.26.21
2. Open brave://welcome

Actual result:

Expected result:

should not be any white border added to brave://welcome page

Reproduces how often:

Easy

Brave version (brave://version info)

Brave	1.26.21 Chromium: 91.0.4472.57 (Official Build) nightly (64-bit)
Revision	e3443317fa07f1e9997e4a9c738eddfefc3c0292-refs/branch-heads/4472_54@{#6}
OS	Windows 10 OS Version 2004 (Build 19041.985)

• Can you reproduce this issue with the current release? No
• Can you reproduce this issue with the beta channel? No
• Can you reproduce this issue with the nightly channel? Yes

Other Additional Information:

• Does the issue resolve itself when disabling Brave Shields? NA
• Does the issue resolve itself when disabling Brave Rewards? NA
• Is the issue reproducible on the latest version of Chrome? NA

Miscellaneous Information:

cc: @brave/legacy_qa @rebron @bsclifton

@bsclifton reappeared the issue #14137

[LaurenWags]

duplicate of #15870