Hook into Gradle build in Android Studio

I want to run some code each time a Gradle build is initialized by either the user or Android Studio. I have tried two different ways of doing this and neither work. Here is my code:

public class PrivacyAnnotationValidator implements StartupActivity {
    public void runActivity(@NotNull Project project) {
        System.out.println("We are printing during the project start!");

        BuildManagerListener listener = new BuildManagerListener() {
            @Override
            public void beforeBuildProcessStarted(@NotNull Project project, @NotNull UUID id) {
                System.out.println("before it builds");
            }

            @Override
            public void buildStarted(@NotNull Project project, @NotNull UUID sessionId, boolean isAutomake) {
                System.out.println("build process initiated!");
            }
        };

        //MessageBus bus = project.getMessageBus();
        MessageBus bus = ApplicationManager.getApplication().getMessageBus();
        bus.connect().subscribe(BuildManagerListener.TOPIC, listener);
        CompilerManager.getInstance(project).addBeforeTask(new PrivacyCompilationTask());
        System.out.println("--------------------------");
    }
}

At no point does anything ever get printed. PrivacyCompilationTask is literally just a System.out.println statement in the execute method.

Any ideas? Thanks!