Update network Dax dialog copy

[marcosholgado]

Task/Issue URL: https://app.asana.com/0/1125189844152671/1187357199382446
Tech Design URL:
CC:

Description:
This PR updates the English copy for the network Dax dialog. The translations are delayed and in the meantime we prefer to do this only in English. Because the copy is different from the previous one we have to check in the CTA if the locale is English to apply the correct substitutions.

New copy
_Heads up! Since Facebook owns instagram.com, I can't stop them from seeing your activity here.

But browse with me, and I can reduce what Facebook knows about you overall by blocking their trackers on lots of other sites._

Steps to test this PR:

1. Launch the app in English.
2. Go to instagram.com
3. New copy should be shown

Non-English:

1. Re-install and launch the app in Spanish or any other language.
2. Go to instagram.com
3. Old copy should be shown (it has an emoji and contains a %).

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Internal references:

Software Engineering Expectations
Technical Design Template

[cmonfortep]

LGTM 👍