[Privacy Choices] Handle "Settings" CTA

[Ecarrion]

closes #9616

Why

This PR handles the actions to be performed when the "Go To Settings" button on the privacy banner is tapped. In particular it:

• Prevents the update network request from being fired if there is no change to the analytics setting.
• Updates the analytics setting after tapping the "Go To Setting" button.
• Navigate to the "Privacy Settings" screen after tapping the "Go To Setting" button.
• Show an error notice when failing to update the analytic setting. (Only WPCom stores)

Demo

WPCom Update Settings

wpcom-change.mov

WPCom Dont Update Settings

change.mov

WPCom Error

wpcom-error.mov

Non WPCom Update Settings

non-wcom-settings.mov

Testing Steps

WPCom Stores

• Log out from the app (to clean the user defaults database)
• Log in to a WPCom store in the EU region (Can use a VPN)
• See the banner being presented
• Toggle the analytics choice
• Tap "Go To Settings"
• See the loading indicator in the save button.
• See that you are navigated to the "Privacy Settings" screen

WPCom Stores

• Log out from the app (to clean the user defaults database)
• Log in to a WPCom store in the EU region (Can use a VPN)
• See the banner being presented
• DO NOT toggle the analytics choice
• Tap "Go To Settings"
• See that you are navigated to the "Privacy Settings" screen
• Notice that there are no loading indicators.

Non WPCom Stores

• Log out from the app (to clean the user defaults database)
• Log in to a non-WPCom store (make sure your phone has an EU locale)
• See the banner being presented
• Toggle the analytics choice
• Tap save
• See that you are navigated to the "Privacy Settings" screen

Error

• Log out from the app (to clean the user defaults database)
• Log in to a WPCom store in the EU region (Can use a VPN)
• See the banner being presented
• Toggle the analytics choice
• Tap "Go to Settings"
• See that you are navigated to the "Privacy Settings" screen
• See the error notice with a retry button

---

• I have considered if this change warrants user-facing release notes and have added them to RELEASE-NOTES.txt if necessary.

[wpmobilebot]

You can test the changes from this Pull Request by:

• Clicking here or scanning the QR code below to access App Center
• Then installing the build number pr9802-2cf6bd8 on your iPhone

If you need access to App Center, please ask a maintainer to add you.

[ThomazFB]

Tested and looks good!