Until commit
9fe05da41370 ("Revert "test: adjust rbd test case guards
to handle new defaults""), default RBD image features were enabled only
in Python API tests; C/C++ API tests were still exercising format 1
(6-7 years after its deprecation!).
Enable format 2 with default image features universally across upgrade
suites.
Fixes: https://tracker.ceph.com/issues/61505
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
(cherry picked from commit
05e24270a2efe85bcdceade87b0e91efcfca3001)