CR-BYOB 0.2.1

Changed

• Updates install from inside the app (GitHub build): Update downloads the new version with a progress bar
  and hands it to Android's installer, instead of going through the browser. Android asks once to allow
  installs from CR-BYOB. On Android 12 and later, updates after the first one may skip Android's confirm
  screen (Google Play Protect may still ask to scan a version it hasn't seen).
  The download is checked against GitHub's checksum and CR-BYOB's signing key before it installs. If a
  scan is streaming, the app asks first, since installing closes it.
• If an update doesn't install (the install permission was left off, it was canceled, or Android blocked it),
  the app says why and offers the release page to download and install it yourself, or another try.
• The version line at the bottom now reads "What's new / Check for app updates" in the GitHub build.
• Softer wording above the donation button: "Avoided buying a Scan Bridge, and want to say thanks with a donation?"