When you create a new project or module using Android Studio, the IDE creates a <module-dir>/proguard-rules.pro file for you to include your own rules. You can also include additional rules from other files by adding them to the proguardFiles property in your module’s build.gradle file.
For example, you can add rules that are specific to each build variant by adding another proguardFiles property in the corresponding productFlavor block. The following Gradle file adds flavor2-rules.pro to the flavor2 product flavor. Now, flavor2 uses all three ProGuard rules because those from the release block are also applied.
