All - Update to Java 8.0 and Android Gradle Plugin 7.0
In order to use FirebaseUI v8.0 or higher your app must use Java 8.0 language featuresa and version 7.x of the Android Gradle Plugin.
Java 8
Add the following to your app's build.gradle
android {
...
// Configure only for each module that uses Java 8
// language features (either in its source code or
// through dependencies).
compileOptions {
sourceCompatibility JavaVersion.VERSION_1_8
targetCompatibility JavaVersion.VERSION_1_8
}
// For Kotlin projects
kotlinOptions {
jvmTarget = "1.8"
}
}
For more information on using Java 8 language features in your app, see the Android documentation.
AGP 7
In your root build.gradle
file make sure you are using AGP 7 or higher:
buildscript {
// ...
dependencies {
// ...
classpath 'com.android.tools.build:gradle:7.0.0'
}
}
This will require installing Gradle 7 and JDK 11 on your machine. For more information on this relase see the Android documentation.