Show privacy statement on launch

[roop]

Fixes #454.

• To configure the privacy statement, we need to edit one or more of the following files:

  • Config/Mac/privacy_statement-eduvpn.json
  • Config/Mac/privacy_statement-letsconnect.json
  • Config/iOS/privacy_statement-eduvpn.json
  • Config/iOS/privacy_statement-letsconnect.json

  • Their format is like: { "title": "Privacy Statement", "lines": [ "each line of the text in order", "", "Done" ] }

    Only the Let's Connect config is populated with releasable text in this PR. The eduVPN config has a dummy text.

• Before building, we should copy the right file to privacy_statement.json, as shall be given in the README

• The app will pick up the text from privacy_statement.json and show an alert with that on launch, iff such an alert has not been previously accepted

[roop]

This is how it looks (these use Let's Connect text for eduVPN app):

iOS:

macOS: