Description of problem:
It looks like that the default harness for RHEL-ALT-7 is restraint 
instead of beah, which goes against bug 1589610 [1]. I guess this is not such a high prio since there's simple workaround, but still would be nice to be fixed if possible


Version-Release number of selected component (if applicable):
Beaker 26.0

How reproducible:
always

Steps to Reproduce:
1. Run e.g. reservesys on RHEL-ALT-7.6

Actual results:
Restraint is used

Expected results:
Beah should be used

Additional info:
Note that there's a workaround to use ks_meta="harness='beah beakerlib'" 
for RHEL-ALT-7.