Fix package com.android.annotations does not exist

Here is how to automatically fix all android to androidx issues for React Native.
1. Please check that you have NPX installed and if not, install it with:
npm install -g npx

2. Add the following two flags to true in your gradle.properties file at ProjectFolder/android/gradle.properties

android.useAndroidX=true
android.enableJetifier=true

3. Execute these lines:

npm install --save-dev jetifier
npx jetify
npx react-native run-android

In your package.json add the following to scripts

  "postinstall" : "npx jetify"

Thats it, you are set, for more info, please go to https://github.com/mikehardy/jetifier