How to troubleshoot "okay google everywhere" missing from voice settings?

This is what I see:

_{(Click image to enlarge)}

And this is what I would like to see:

I am using Motorola Moto G 3rd generation (2015), 1 GB RAM, 8 GB storage; XT1541

I have already tried a few things:

• I'm already using the latest version of Android as of now: 5.1.1 Lollipop.


• I'm using the latest version of the Google now application: 5.1.17.19.arm


• I have tried to search for the magic phrase "okay Google everywhere"


• I have tried to uninstall and reinstalled the Google application. I think it was just a downgrade to version 4 of the app because the Google Play store told me that it is a built in application.


• restarting the Google application by force quitting the app and/or restarting the whole phone.



• switching the local from UK English to US English wherever I could find it in the phone settings.


• and maybe some other things too.

But nothing seemed to help.

What could be causing the missing option? What else could I try to make it show up?

I am also thinking about contacting support. If I do so, should I be contacting Google or Motorola?

Edit:

• The version of my "Google Now Launcher" application is 1.1.1.1706998


• I have even tried factory reset with and without restoring from backup; no success.