Add Filecoin to list of buy options on Ramp

[HEagle18]

It's now become available. see #ramp-shared slack channel.

Description

Steps to Reproduce

Actual result:

Expected result:

Reproduces how often:

Brave version (brave://version info)

Version/Channel Information:

• Can you reproduce this issue with the current release?
• Can you reproduce this issue with the beta channel?
• Can you reproduce this issue with the nightly channel?

Other Additional Information:

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

Miscellaneous Information:

[srirambv]

Verification passed on

Brave	1.43.79 Chromium: 104.0.5112.102 (Official Build) beta (64-bit)
Revision	8e5396254975ef939f2ef7d0bd334e48a052b536-refs/branch-heads/5112@{#1478}
OS	Linux

• Verified steps from brave/brave-core#14236
• Verified Filecoin is available to buy via Ramp

24123-Linux.mp4

---

Verification passed on

Brave	1.43.79 Chromium: 104.0.5112.102 (Official Build) beta (64-bit)
Revision	8e5396254975ef939f2ef7d0bd334e48a052b536-refs/branch-heads/5112@{#1478}
OS	Windows 11 Version 21H2 (Build 22000.795)

• Verified steps from brave/brave-core#14236
• Verified Filecoin is available to buy via Ramp

24123-Windows.mp4

---

Verification passed on

Brave	1.43.79 Chromium: 104.0.5112.102 (Official Build) beta (64-bit)
Revision	8e5396254975ef939f2ef7d0bd334e48a052b536-refs/branch-heads/5112@{#1478}
OS	macOS Version 12.4 (Build 21F79)

• Verified steps from brave/brave-core#14236
• Verified Filecoin is available to buy via Ramp

24123-macOS.mov