Utilizes assertIn - tests/virt

Using assertTrue and the 'in' operator to test
if an element is in a sequence is too python2.4.
Our unit testing framework supports assertIn,
which was created for these types of tests.
Using assertIn will enhance readability of the test scripts.

Change-Id: Ifa0f7e12a1ba84052e1e64ed2775056fafd2b13b
Merge "Utilizes assertIn - tests/virt"