Might be worth mentioning in docs

[srfrnk]

In addition to what's specified in README... I had to:

• In .../android/app/build.gradle - change minSdkVersion to 20 (or higher)
• In .../android/gradle.properties - Add android.useAndroidX=true and
  android.enableJetifier=true

[lambasoft]

It sucks that minSdkVersion must be equal or higher than 20 :(

[myselfuser1]

This might help https://www.youtube.com/watch?v=uMvGpBOT0ZY