Update default NTP wallpaper on Desktop

[simonhong]

This is sub task of #18568 for replacing default bg image on Desktop.

STR:

1. Launch browser with clean profile
2. Open NTP and check Dylan Malval's image is displayed till NTP Background Images component is loaded.

[stephendonner]

Verified PASSED using

Brave	1.33.52 Chromium: 95.0.4638.69 (Official Build) nightly (x86_64)
Revision	6a1600ed572fedecd573b6c2b90a22fe6392a410-refs/branch-heads/4638@{#984}
OS	macOS Version 11.6.1 (Build 20G224)

Steps:

1. disconnected from Wi-Fi
2. new profile
3. launched Brave
4. opened a new-tab page
5. confirmed the image is Dylan Malval's
6. opened a few more new-tab pages
7. confirmed the image is still Dylan Malval's
8. reconnected to Wi-Fi
9. loaded brave://components and saw the NTP Background Images downloaded version 1.0.4
10. confirmed after enabling Wi-Fi that subsequent new-tab page loads brought in additional images

example	example	example	example

---

Verified PASSED using

Brave	1.33.82 Chromium: 96.0.4664.45 (Official Build) beta (64-bit)
Revision	76e4c1bb2ab4671b8beba3444e61c0f17584b2fc-refs/branch-heads/4664@{#947}
OS	Windows 10 Version 20H2 (Build 19042.1348)

Steps:

1. disconnected from Wi-Fi
2. new profile
3. launched Brave
4. opened a new-tab page
5. confirmed the image is Dylan Malval's
6. opened a few more new-tab pages
7. confirmed the image is still Dylan Malval's
8. reconnected to Wi-Fi
9. loaded brave://components and saw the NTP Background Images downloaded version 1.0.4
10. confirmed after enabling Wi-Fi that subsequent new-tab page loads brought in additional images

example	example	example

---

Verified PASSED using

Brave	1.33.82 Chromium: 96.0.4664.45 (Official Build) beta (64-bit)
Revision	76e4c1bb2ab4671b8beba3444e61c0f17584b2fc-refs/branch-heads/4664@{#947}
OS	Windows 10 Version 20H2 (Build 19042.1348)

Steps:

1. disconnected from Wi-Fi
2. new profile
3. launched Brave
4. opened a new-tab page
5. confirmed the image is Dylan Malval's
6. opened a few more new-tab pages
7. confirmed the image is still Dylan Malval's
8. reconnected to Wi-Fi
9. loaded brave://components and saw the NTP Background Images downloaded version 1.0.4
10. confirmed after enabling Wi-Fi that subsequent new-tab page loads brought in additional images

example	example	example

[LaurenWags]

@brave/legacy_qa this can be tested along side #19129