Update `Add to Brave` text on extensions web store

[rebron]

Description

At the chrome web store (preview and upcoming redesign), the Add to Brave button has regressed and shows Add to Chrome. Needs to show Add to Brave.

Steps to Reproduce

1. Go to https://chromewebstore.google.com/detail/webchatgpt-chatgpt-with-i/lpfemeioodjbpieminkklglpmhlngfcn
2. Notice Add to Chrome button
3. Should say Add to Brave with our styling.

Actual result:

Expected result:

https://chrome.google.com/webstore/detail/webchatgpt-chatgpt-with-i/lpfemeioodjbpieminkklglpmhlngfcn

Reproduces how often:

Easily.

Brave version (brave://version info)

chrome web store preview version

Version/Channel Information:

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

Other Additional Information:

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

Miscellaneous Information:

[kjozwiak]

The above requires 1.58.128 or higher for 1.58.x verification 👍

[GeetaSarvadnya]

Verification PASSED on

Brave | 1.58.128 Chromium: 117.0.5938.88 (Official Build) (64-bit)
-- | --
Revision | 171b8e11a776dc3f1472bc4f593caf36463b40c7
OS | Windows 10 Version 22H2 (Build 19045.3448)

Using STR from https://github.com/brave/brave-core/pull/20178#issuecomment-1724714905, visited https://chrome.google.com/webstore and selected to view the "Preview" of redesign. Compared 1.58.127 and 1.58.128 and confirmed that Brave was being used rather than Chrome as per the following:

1.58.127	1.58.128	1.58.128

[LaurenWags]

Verified with

Brave | 1.58.128 Chromium: 117.0.5938.88 (Official Build) (x86_64)
-- | --
Revision | 171b8e11a776dc3f1472bc4f593caf36463b40c7
OS | macOS Version 13.5.2 (Build 22G91)

Using STR from https://github.com/brave/brave-core/pull/20178#issuecomment-1724714905, visited https://chrome.google.com/webstore and selected to view the "Preview" of redesign. Compared 1.58.127 and 1.58.128 and confirmed that Brave was being used rather than Chrome as per the following:

1.58.127	1.58.128	1.58.128

[LaurenWags]

@rebron @zenparsing looks like when viewing the chrome store redesign via the "Preview" option, the "Add to Brave" button is pill shaped (see my screenshots above), not the rectangle with rounded corners as it was previously/in existing webstore (see @GeetaSarvadnya screenshots). Is this ok?

[rebron]

That's ok with the button shape. We just want the text to be updated.

[btlechowski]

Verified PASSED

Brave	1.58.128 Chromium: 117.0.5938.88 (Official Build) (64-bit)
Revision	171b8e11a776dc3f1472bc4f593caf36463b40c7
OS	Linux

Verified test plan from the description