Android/Gradle: conditionally apply plugin based on build type

Based on Stefan Oehme, a Gradle core developer, he said:

Plugins can't be applied to only "part of your project". They are either applied or not. What is the use case where this becomes a problem for you?

So, the answer is this is not possible. I have exposed my use cases where this is becomes a problem and I'll see what hi says about it.

With Gradle 4.6, the following works:

if (getGradle().getStartParameter().getTaskRequests().toString().contains("Release")) {
    apply plugin: 'testfairy'
} else if (getGradle().getStartParameter().getTaskRequests().toString().contains("Debug")) {
    apply plugin: 'io.fabric'
}

Here is a workaround solution I used. The idea is to introduce an Env variable and only apply the plugin in some specific env.

if (System.getenv("PROJECT_ENV") == "Release") {
    apply plugin: 'your plugin'
}

Here was the solution I had that did not crash the app. Other solutions did crash when the class was finally called with a Class not found exception.

def tasks = gradle.startParameter.taskNames[0] ?: ""
if (tasks.toLowerCase().contains("prod")) {
    println "Firebase-Performance pluign applied..."
    apply plugin: 'com.google.firebase.firebase-perf'
}