public int getImportance() {
        if (Build.VERSION.SDK_INT >= 24) {
            return mNotificationManager.getImportance();
        } else {
            return IMPORTANCE_UNSPECIFIED;
        }
    }
Returns the user specified importance for notifications from the calling package.

@return An importance level, such as {@link #IMPORTANCE_DEFAULT}.
android/android_framework/base/src/main/java/github/tornaco/android/thanos/core/compat/NotificationManagerCompat.java