Freemium PIR: Ship Review Changes - Updated New Tab Banner UI

[aataraxiaa]

Task/Issue URL: https://app.asana.com/0/1206488453854252/1208677018043704/f

Description: Updates the Freemium PIR new tab page promotion banner as follows:

1. Changes the icon
2. Adds a title
3. Changes the description text and color
4. Adds optional bold text to the promotion description text

Note: Targeting release branch as I want these changes to be available publicly next week

Test Prerequisites

1. Set yourself as an internal user via Debug menu → Set Internal User State
2. Disable/Signout of Privacy Pro via Settings menu → PP → Remove from this device
3. Select Debug menu → Freemium -> Reset all Freemium State
4. Select Debug menu → Freemium -> Enroll into Experiment

Steps to test this PR:

1. Relaunch the browser
2. Ensure you see the promotion on the new tab page and that it appears as below:

Definition of Done:

• Does this PR satisfy our Definition of Done?

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Internal references:

Pull Request Review Checklist
Software Engineering Expectations
Technical Design Template
Pull Request Documentation