Mise en place certificate pinning

[yostyle]

Content

Add certificate pinning feature only on Gplay release build.

Motivation and context

tchapgouv/tchap-product#373

Screenshots / GIFs

Tests

• Step 1
• Step 2
• Step ...

Tested devices

• Physical
• Emulator
• OS version(s):

Checklist

• Changes have been tested on an Android device or Android emulator with API 23
• UI change has been tested on both light and dark themes
• Accessibility has been taken into account. See https://github.com/element-hq/element-x-android/blob/develop/CONTRIBUTING.md#accessibility
• Pull request is based on the develop branch
• Pull request title will be used in the release note, it clearly define what will change for the user
• Pull request includes screenshots or videos if containing UI changes
• Pull request includes a sign off
• You've made a self review of your PR

[NicolasBuquet]

LGTM!

[NicolasBuquet]

Why does F-Droid version need to allow clear traffic on local network ? VPN need on NEO devices ?

[yostyle]

Clear text traffic can be used only for specific hosts during development :

• localhost
• 127.0.0.1
• etc ...

It's the default configuration provided by Element X for all variants (Fdroid and Gplay). I move it for Fdroid only.