How to replace a string for a buildvariant with gradle in android studio?

Question

I have two flavors of my project:

flavor1 -> packagename: com.example.flavor1 
flavor2 -> packagename: com.example.flavor2

Now I want

Answer 1

I use almost exactly the approach you wanted to. The replaceInManfest is also generic and can be used for other placeholders as well. The getGMapsKey() method just returns the appropriate key based on the buildType.

applicationVariants.all { variant ->
    def flavor = variant.productFlavors.get(0)
    def buildType = variant.buildType
    variant.processManifest.doLast {
        replaceInManifest(variant,
            'GMAPS_KEY',
            getGMapsKey(buildType))
    }
}

def replaceInManifest(variant, fromString, toString) {
    def flavor = variant.productFlavors.get(0)
    def buildtype = variant.buildType
    def manifestFile = "$buildDir/manifests/${flavor.name}/${buildtype.name}/AndroidManifest.xml"
    def updatedContent = new File(manifestFile).getText('UTF-8').replaceAll(fromString, toString)
    new File(manifestFile).write(updatedContent, 'UTF-8')
}

I have it up on a gist too if you want to see if it evolves later.

I found this to be a more elegant and generalizable approach than the others (although the token replacement just working would have been nicer).