Configure scenario clients with region

When configuring the clients make sure that the correct region is
used.

Change-Id: I2066180aaa85532e81dc37b3bd593e596234e0e1
Closes-Bug: 1248829
Adapt scenario readme with real-life aspect

As discussed in the design session a scenario test should be focused on
a real-life use case.

Change-Id: I5cf5518bc7fadfd49b107b93903ab4df093057a1
Merge "Configure scenario clients with region"
Merge "Adapt scenario readme with real-life aspect"