update_available_android 2.0.0-nullsafety

Android platform implementation of update_available

2.0.0-nullsafety

• Migration to null-safety
• Changed version to pub_semver

Disclaimer: I think that it's correctly working, but as I am not using null-safety in production yet, I couldn't propertly test it. I am going to ask to someone to test it for me and, as soon it's safe to be used in production, I publish it as stable.

1.0.1+1

• Update README.md

1.0.1

• Remove pubspec.lock

1.0.0

• Initial version