Keep list of countries visited last n days

[Apisov]

Issue

In order to fetch data from EN server we need a list of the regions visited by the user.

TODO

• Add the ACTION_NETWORK_COUNTRY_CHANGED broadcast to detect when users change country
• Save list of countries visited in the last n days
• Delete the countries that were visit more than n days before
• Update the list every n days

Resources

n should be equal to the number that PHAs require for relevant exposure period. By default it's 14 following EN requirements for exposure keys.