Hiding API keys in local.properties

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

apiKey=<value>

2. Add to the build.gradle.kts file (module-level):

import com.android.build.gradle.internal.cxx.configure.gradleLocalProperties

3. Add to the android { defaultConfig { } } block of your module-level build.gradle.kts file:

android {
    // ...
    
    defaultConfig {
        // ...
        buildConfigField("String", "API_KEY", gradleLocalProperties(rootDir).getProperty("apiKey"))

    }
    
    // ...
    
}

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

val apiKey = BuildConfig.API_KEY