Detecting foreground activity from service

accessibilityservice.xml

<?xml version="1.0" encoding="utf-8"?>
<!-- These options MUST be specified here in order for the events to be received on first
 start in Android 4.1.1 -->
<accessibility-service
    xmlns:tools="http://schemas.android.com/tools"
    android:accessibilityEventTypes="typeWindowStateChanged"
    android:accessibilityFeedbackType="feedbackGeneric"
    android:accessibilityFlags="flagIncludeNotImportantViews"
    android:description="@string/app_name"
    xmlns:android="http://schemas.android.com/apk/res/android"
    tools:ignore="UnusedAttribute"/>

AndroidManifest.xml

    <application>
        <service
            android:label="BLABLABLA"
            android:name=".service.WindowChangeDetectingService"
            android:permission="android.permission.BIND_ACCESSIBILITY_SERVICE">
            <intent-filter>
                <action android:name="android.accessibilityservice.AccessibilityService"/>
            </intent-filter>
            <meta-data
                android:name="android.accessibilityservice"
                android:resource="@xml/accessibilityservice"/>
        </service>
</application>

WindowChangeDetectingService.kt

class WindowChangeDetectingService : AccessibilityService() {

    override fun onServiceConnected() {
        super.onServiceConnected()

        //Configure these here for compatibility with API 13 and below.
        val config = AccessibilityServiceInfo()
        config.eventTypes = AccessibilityEvent.TYPE_WINDOW_STATE_CHANGED
        config.feedbackType = AccessibilityServiceInfo.FEEDBACK_GENERIC

        if (Build.VERSION.SDK_INT >= 16)
        //Just in case this helps
            config.flags = AccessibilityServiceInfo.FLAG_INCLUDE_NOT_IMPORTANT_VIEWS

        serviceInfo = config
    }

    override fun onAccessibilityEvent(event: AccessibilityEvent) {
        if (event.eventType == AccessibilityEvent.TYPE_WINDOW_STATE_CHANGED) {
            if (event.packageName != null && event.className != null) {
                val componentName = ComponentName(
                        event.packageName.toString(),
                        event.className.toString()
                )

                val activityInfo = tryGetActivity(componentName)
                val isActivity = activityInfo != null
                if (isActivity)
                    Timber.d("CurrentActivity: %s", componentName.flattenToShortString())
            }
        }
    }

    private fun tryGetActivity(componentName: ComponentName): ActivityInfo? {
        try {
            return packageManager.getActivityInfo(componentName, 0)
        } catch (e: PackageManager.NameNotFoundException) {
            return null
        }

    }

    override fun onInterrupt() {}
}