Implement Social Media Blocking

[jumde]

Test Plan

Specified here: brave/brave-core#6899

Description

Implement social media blocking settings on Android similar to Desktop:

Designs

Add social media blocking settings in the Brave Shields & Privacy section, under Brave Stats

Assets

Figma: https://www.figma.com/file/c5Sq98FXH6oz1z3FL8K3eN/Android-Brave-Shields?node-id=0%3A420

[anthonypkeane]

@karenkliu when you have a moment mock up an Android design for this one and add it here? Thank you.

[karenkliu]

Designs added!

[pes10k]

Just noting that this issue was also (indirectly) raised in a community thread, if that helps with prioritization:

https://community.brave.com/t/found-https-2a-firebase-app-com-in-allowed-cookies/154373 as discussed in #11679

[jonathansampson]

Recently mentioned here as well: https://twitter.com/nairulislam/status/1309141451859726337

[btlechowski]

Verification passed on Brave v1.16.68 on Samsung Galaxy Tab S5e (Android 9.0)

Verified test plan from brave/brave-core#6899

1. Verified social media blocking options is listed under privacy and Google/Facebook/Twitter is enabled by default and Linkedin is disabled
   

2. Verified toggle settings and reloading the pages works correctly on https://fmarier.github.io/brave-testing/social-widgets.html

3. Verified test login works on the following sites
   • https://quora.com FB login works when FB setting is enabled
   • https://www.expensify.com/ Turned off: Went through login process, but was unable to login; Turned on: Was able to login
4. Verified the sites from the following issues only work when respective setting is enabled

brave/browser-laptop#2014

brave/browser-laptop#1208

5. Verified Google login for https://pinterest.com/login/ only works when the option is enabled
6. Verified disabling Google Login and navigating to Settings > Site Settings > Cookies doesn't show any exceptions in the list
   

Logged #12336 for missing translations

---

Verification PASSED on Samsung S10+ running Android 10 using 1.16.68 CR: 86.0.4240.111.

• ensured that Settings > Privacy > Social Media Blocking exists and has the following enabled as default:

[x]  Allow Google login buttons on third party sites
[x]  Allow Facebook logins and embedded posts
[x]  Allow Twitter embedded tweets
[ ]  Allow LinkedIn embeds

• Verified that the following websites are working as expected:

https://quora.com FB login works when FB setting is enabled 
https://www.expensify.com Google Login only opens a new tab when Google setting is enabled

• Visited https://fmarier.github.io/brave-testing/social-widgets.html and ensured that the switches under Settings > Privacy > Social Media Blocking worked correctly:

Enabled (Default)	Disabled

Checking brave/browser-laptop#2014:

Disabled	Enabled

Checking brave/browser-laptop#1208:

Disabled	Enabled

Ensured that you cannot login into https://pinterest.com/login when FB/Google are disabled:

FB Disabled	FB Enabled

Ensured there's no Google cookie exceptions under Settings > Site Settings > Cookies when Google Login has been disabled:

Disabled	Enabled