Setting a manifestPlaceHolders

setPlaceHolders.gradle

 buildTypes {
        release {
            minifyEnabled false
            shrinkResources false
            proguardFiles getDefaultProguardFile('proguard-android-optimize.txt'), 'proguard-rules.pro'
            testCoverageEnabled false
            manifestPlaceholders = [
                    appIcon:  "@mipmap/ic_release"
            ]
        }

        debug {
            applicationIdSuffix ".debug"
            debuggable true
            minifyEnabled false
            shrinkResources false
            testCoverageEnabled true
            manifestPlaceholders = [
                    appIcon:  "@mipmap/ic_debug"
            ]
        }
    }