Revert "Merge "Remove running of one Heat test in system test 'Heat HA'" into stable/5.1"

This reverts commit f183e1837d26d3794764be5dfff0ab5a54a1849b, reversing
changes made to 8ef433e939425eabd1034c0b70e90bdf888b69fd.

Change-Id: I68f8676ac5c4b544d66ac26bc63c22d803d49da3