Release v21-rc1

Reusable toggle switch control (#720)

* add toggleSwitchInput #697

* Add styling #697

* Add label #697

* Fix names. #697

* Remove test code #697

Release v20

• Status bar is not flickering now (#691)
• Bitcoin node connections are tuned for more reliable operation (#684)
• Automatic reconnection to indexer servers (#679)
• Indexer addresses now can be hostnames. Added DNS resolving step (#680)

v15: Update android-version.nix

Bump version to 15