[BUG]: Aodh alarm cannot be created using the document

[Amit Bhardwaj]

This bug tracker is for errors with the documentation, use the following as a template and remove or add fields as you see fit. Convert [ ] into [x] to check boxes:

- [x] This doc is inaccurate in this way: Step 3: Creating Aodh Alarms -> Alarm cannot be created using the command. There is a whole lot of stuff that is to be done in the background at multiple levels as mentioned in https://bugs.launchpad.net/senlin/+bug/1801755
Even after using the steps, the issue remains the same.

- [ ] This is a doc addition request.
- [ ] I have a fix to the document that I can paste below including example: input and output.

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-----------------------------------
Release: 7.0.0.0rc2.dev3 on 2018-07-12 17:44:36
SHA: 88dacd604ab5496ea231c959fa7d83996dfc639f
Source: https://git.openstack.org/cgit/openstack/senlin/tree/doc/source/scenarios/autoscaling_ceilometer.rst
URL: https://docs.openstack.org/senlin/stein/scenarios/autoscaling_ceilometer.html