How to apply plugin to only one flavor in gradle?

I simply used apply plugin: 'com.google.gms.google-services' inside the flavor in app level build.gradle and it works just fine.

productFlavors {
    ..... your other flavors ....
    yourFlv {
        ....
        ....
        apply plugin: 'com.google.gms.google-services'
    }
}

No extra step needed.

1. Define variable - def fl

2. Initialize variable in you Flavours (and/or builds)

       productFlavors {
   
               freeFlavour {
                   (...)
                   fl = "free"
               }
   
               paidFlavour {
                   (...)
                   fl = "paid"
               }
           }
   

3. Use if statement -

   if (fl == "free") { apply plugin: something }

Tried different solutions, but none of them worked for me. This is what I came up with and seems to work as far as I tested:

build.gradle

productFlavors {
    someFlavorWithGoogleGcm {
        dimension "type"
        applicationId "com.example.withGcm"
        ext.useGoogleGcm = true
    }
    someFlavorWithoutGoogleGcm {
        dimension "type"
        applicationId "com.example.withoutGcm"
    }
}

And outside the configuration, inside the build.gradle file:

android.productFlavors.each { flavor ->
    if (getGradle().getStartParameter().getTaskRequests().toString().toLowerCase().contains(flavor.name) && flavor.ext.useGoogleGcm) {
        println("Building flavor with Google GCM [${flavor.name}] - applying plugin")
        apply plugin: 'com.google.gms.google-services'
    }
}

Use this code:

if (!getGradle().getStartParameter().getTaskRequests()
        .toString().contains("Develop")){
    apply plugin: 'com.google.gms.google-services'
}

getGradle().getStartParameter().getTaskRequests().toString() returns something like [DefaultTaskExecutionRequest{args=[:app:generateDevelopDebugSources],projectPath='null'}] so as stated in the comments Develop must start with an uppercase.