Add create instance action in murano simple test

Murano simple test usually fails on ubuntu,
because if image doesn't cached by glance
creating instance with murano image takes a long time,
this time are greater than test's timeout.
Add instance creation before running murano ostf test,
it allows to cache image in glance before running tests.

Change-Id: I988b88bf49d3adbfa72114081f6de8b423bef3f4
Closes-bug: #1334238
Merge "Add create instance action in murano simple test"