build.gradle

android {
    ...

    signingConfigs {
        release {
            storeFile file("someDirectory/my_keystore.jks")
            storePassword "my_store_pass_here"
            keyAlias "my_key_alias_here"
            keyPassword "my_key_pass_here"
        }
    }

    buildTypes {
        release {
            signingConfig signingConfigs.release
            minifyEnabled false
            proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
        }
    }
}