Add Base to preloaded EVM networks

[onyb]

Description

.

Steps to reproduce

N/A

Actual result

N/A

Expected result

1. Base is listed as a preloaded network in Settings > Web3 > Wallet Networks
2. Base balances are displayed in the wallet Portfolio

Reproduces how often

Easily reproduced

Brave version (brave://version info)

N/A

Channel information

• release (stable)
• beta
• nightly

Reproducibility

• with Brave Shields disabled
• with Brave Rewards disabled
• in the latest version of Chrome

Miscellaneous information

No response

[kjozwiak]

The above requires 1.74.45 or higher for 1.74.x verification 👍

[srirambv]

Verification passed on

Brave	1.74.45 Chromium: 132.0.6834.57 (Official Build) beta (64-bit)
Revision	b8c4625f59984c01cb763d30442350dec7f727cf
OS	Windows 11 Version 23H2 (Build 22631.4602)

• Verified steps from issue description
• Verified Aurora is removed from default network list on a clean profile
• Verified if Aurora is set as default its retained as the the default network post upgrade
• Verified if Aurora is not set as default it is removed from the list of default network
• Verified Base is added as a default network on both clean and upgrade

42885.mp4