Bug 1793501

Description of problem:
Depending on which DBus method is called, the subscription describing JSON data RHSM returns has different subscription start and end date formatting.

In output from AutoAttach() the date looks like this:
2020-11-04T04:59:59+0000

In output from GetPools() with “pool_subset” -> “consumed”  it looks like this:
11/04/2020 
or 
11/04/20

I have seen the first when calling RHSM DBuS API on an installed system while I'm getting the second one consistently in the installation environment. I guess it'S dependent on the locale, maybe even created with the locale dependent "%x" argument to strftime ? (https://docs.python.org/3/library/datetime.html#strftime-and-strptime-format-codes) 

Another issue is that the first format contains data about time while the other does not, so the time data might be getting lost in GetPools() output ?

In any case it would be good to have a single consistent machine readable time formatting across all the JSON data returned by RHSM, preferably using one of the ISO standards for time and date formatting, which should be nowadays widely supported by relevant C & Python libraries. This date and time format should be then also specified in the RHSM DBus API documentation.

Version-Release number of selected component (if applicable):
1.26.9-1

How reproducible:
always

Steps to Reproduce:
1. register
2. call AutoAttach() & GetPools() over DBUs

Actual results:
Returned dates are in different format.

Expected results:
All returned dates are in the same format.