We have SharePoint 2013 on prem.  We can open an excel spreadsheet using Chrome on our android device and can view it just fine.

We are not able to edit it. 

I have found posts about MS providing that capability but cannot find where they have yet.  Can someone tell me if editing excel using Chrome on an android device is available yet?  If not when can that be expected?  It was announced over 2 years ago by MS.  If it is available what do I need to do to make it work?

This is the wrong forum, you want the O365 or SharePoint forums.

On android you have two options; Office Web Apps which is a browser based set of tools to edit documents, or Office for Android which is an Android application made by MS to allow editing.

https://products.office.com/en-gb/mobile/office-android-tablet