Allow not the same sequence in container_formats and disk_formats

In glance v1, If container_format is one of ['ami', 'ari', 'aki'],
then disk_format must be same with container_format, otherwise
we will get an exception:
     "Invalid mix of disk and container formats. When setting a disk
      or container format to one of 'aki', 'ari', or 'ami', the
      container and disk formats must match."

And in tempest.conf, the container_format and disk_format may be of
different item sequence, such as:
    container_formats = ami,ari,aki,bare
    disk_formats = ari,ami,aki,vhd
In this case, the testcase may fail unexpectedly, so this is to
select one in disk_formats list that is same with container_format,
to avoid the unexpected failure.

Change-Id: Ia64e9ad70c78d8f26f117f90384756f78de164d8
1 file changed