Enable Proguard using gradle

For enabling Proguard configurations for your application you need to enable it in your module-level gradle file. You need to set the value of minifyEnabled to true.

buildTypes {
        release {
            minifyEnabled true
            proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
        }
    }

The above code will apply your Proguard configurations contained in the default Android SDK combined with the “proguard-rules.pro” file on your module to your released apk.