Disable file injection tests until bug/1882421
Disable file injection tests until bug/1882421

File injection tests are failing consistently on
python3 and make tempest-all job fail.
- https://zuul.openstack.org/build/9625ced67fad4fa48ad43185a3ee256f

once nova bug is fixed, we can unskip it.
- https://bugs.launchpad.net/nova/+bug/1882421

Related-Bug: #1882421
Change-Id: I3b683209519e6faea6305eb8d90546f46344981f

openstack/tempest,openstack/tempest