Fix issues with check_instance_shared_storage.

Commit 52f6981aa35e27c48587ad2320891db8364edd02 added a new method to
the compute rpc API.  A test was not added to compute/test_rpcapi.py for
this.  I noticed when I hit a bug in a patch I'm working on that would
have been caught by this test.

The addition to the client side also missed adding the version number
that was required for this method to be supported.

Since the versioning wasn't set up fully, this patch goes ahead and adds
the instance to the data being sent, as well.  It's more consistent,
even if not used (yet).

Fix bug 1167356.

Change-Id: I46055a666fe3cf4a923002f11d22c3b6a6d020e2
Merge "Fix issues with check_instance_shared_storage."