Gradle plugin transition from 0.12/0.13 to 0.14/1.0.0

build.gradle

// enable proguard on all version of the android gradle plugin
release {
    if (!properties.findAll{it.key == 'runProguard'}.isEmpty()) {
        runProguard true
    } else if (!properties.findAll{it.key == 'minifyEnabled'}.isEmpty()) {
        minifyEnabled true
    }
}

// detect proguard in a variant
applicationVariants.all { variant ->
    def usesProguard = false
    if (!variant.buildType.properties.findAll{it.key == 'runProguard'}.isEmpty()) {
        usesProguard = variant.buildType.runProguard
    } else if (!variant.buildType.properties.findAll{it.key == 'minifyEnabled'}.isEmpty()) {
        usesProguard = variant.buildType.minifyEnabled
    }
}