Fix consistency groups test credentials

This patch fixes the test for consistency groups, changing it to an admin
test in order to perform required operations.

Change-Id: I5f7fd8d62ace7d880a27697cf2b15fbb13cde706
Depends-On: I8bdfc31bb2baeabe1d599ea6e9be3c473531f8b6
Closes-Bug: #1789944
3 files changed