brave://settings/ page is empty in Guest window

[GeetaSarvadnya]

Description

brave://settings/ page is empty in Guest window

Steps to Reproduce

1. Open 1.30.36 nightly build
2. Open a Guest window
3. Navigate to brave://settings
4. settings page is empty

Actual result:

Expected result:

Reproduces how often:

Easy

Brave version (brave://version info)

Brave	1.30.36 Chromium: 93.0.4577.51 (Official Build) nightly (64-bit)
Revision	762d21050e2da59930c784c09b134d0b0b148188-refs/branch-heads/4577@{#915}
OS	Windows 10 OS Version 2009 (Build 19043.1165)

Version/Channel Information:

• 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 @mkarolin

[LaurenWags]

Verified passed with

Brave | 1.29.74 Chromium: 93.0.4577.58 (Official Build) (x86_64)
-- | --
Revision | c4410ece044414ea42fa4ba328d08195e818a99c-refs/branch-heads/4577@{#1076}
OS | macOS Version 10.15.7 (Build 19H1323)

Verified STR from description.
Confirmed able to navigate to brave://settings from hamburger menu and manually in URL bar when using a Guest window.
Reproduced crash reported with #15053.
Confirmed able to change a couple of settings (search engine, shield settings) in Guest window settings and those were reflected in the Guest window but not in a normal window.