Hiding API keys in local.properties

1. Add the API key to your local.properties file:

apiKey=<value>

1. Add to the root level of your app-level build.gradle file:

def localProperties = new Properties()
localProperties.load(new FileInputStream(rootProject.file("local.properties")))

1. Add to the android { defaultConfig { } } block of your app-level build.gradle file:

android {
    // ...
    
    defaultConfig {
        // ...
        buildConfigField "String", "API_KEY", localProperties['apiKey']

    }
    
    // ...
    
}

1. Sync Gradle and build the project. You can now reference the key:

val apiKey = BuildConfig.API_KEY