Enable nonvoting testing in VPP ARM verify jobs

Enable nonvoting testing in VPP ARM verify jobs

Enable testing utilizing parallel test execution for ARM jobs with
parallel test execution code, which has been merged in 1810 and update
the OS for these jobs to Ubuntu1804.

Create new jobs for branches without parallel test execution which don't
have testing enabled and retain the OS.

Also exclude some currently failing tests which will be enabled once
the underlying issues are fixed.

Change-Id: I5bbb1348a5a00676759753e5cf66ab65ce55e57d
Signed-off-by: juraj.linkes <juraj.linkes@pantheon.tech>