Update bookmarks folder icon on the bookmarks bar

[simonhong]

This issue is only for bookmarks bar folder image and is sub issue of #7312

[stephendonner]

Verified PASSED using

Brave	1.28.85 Chromium: 92.0.4515.93 (Official Build) beta (x86_64)
Revision	6eb43ff7850a1d710c3f827a0555737c74edab5c-refs/branch-heads/4515@{#1378}
OS	macOS Version 11.4 (Build 20F71)

Steps:

1. new profile
2. launch Brave
3. either populate or import bookmarks, and ensure View | Always show bookmarks is toggled to On
4. look at the bookmarks bar's folder icons
5. confirmed the icons were new and matched the style over in Replaced folder image from bookmarks bar brave-core#9424

light

before	after

dark

before	after

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Verification passed on

Brave | 1.28.92 Chromium: 92.0.4515.107 (Official Build) beta (64-bit)
-- | --
Revision | 87a818b10553a07434ea9e2b6dccf3cbe7895134-refs/branch-heads/4515@{#1634}
OS | Windows 10 OS Version 2004 (Build 19041.1110)

• Confirmed bookmarks folders icon/image changed to brave branded icon

Light theme

Dark theme

• Confirmed subfolder icon/images are changed to brave branded icon

Light theme

Dark theme

• Logged Brave branded bookmarks bar subfolder images are not shown clearly in Private tabs - Follow up of #16940 - Brave branded bookmarks subfolder images are not shown clearly in Private tabs #17214
• Encountered Use Brave branded icons for Bookmarks manager #7312

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Verification passed on

Brave	1.28.92 Chromium: 92.0.4515.107 (Official Build) beta (64-bit)
Revision	87a818b10553a07434ea9e2b6dccf3cbe7895134-refs/branch-heads/4515@{#1634}
OS	Ubuntu 18.04 LTS

Verified expected behavior from brave/brave-core#9424

• Confirmed bookmarks folders icon/image changed to brave branded icon

Light theme

Dark theme

• Confirmed subfolder icon/images are changed to brave branded icon

Light theme

Dark theme