title: Android: How do you check if a particular AccessibilityService is enabled
body: <p>I've written an Android app that requires the use of the <a href="https://d.android.com/reference/android/accessibilityservice/AccessibilityService" rel="noreferrer"><code>AccessibilityService</code></a>.
  I know how to check to see if Accessibility is enabled or disabled on the phone, but I cannot work out a way to determine if my app has been specifically enabled within the accessibility menu.</p>
  
  <p>I'm wanting to prompt the user if the <code>AccessibilityService</code> is not running, but can't find a good way of doing this.
  Is there any API methods that I might be missing that would let me know which accessibility services are enabled on the device?</p>