Currently, `wait_for_prepare_pod` only waits until 1 prepare pod and 1
OSD pod are in Running state.
So if `wait_for_ceph_to_be_ready` failed after `wait_for_prepare_pod`
succeeded, there are 4 possible cases:
1. some prepare pods didn't start correctly;
2. some prepare pods didn't finish correctly;
3. some OSD pods didn't start correctly; or
4. all prepare pods and OSD pods worked correctly, but some other
process failed.
As far as I understand, the number of prepare pods on the GitHub CI is
always 1, so cases 1 and 2 are not problematic. However, it is hard to
distinguish the other two cases from the CI log.
To solve the above problems, this patch makes wait_for_prepare_pod wait
for all OSD pods to become running state. If wait_for_prepare_pod
timeouts before the OSD pods become running state, this will be a strong
indication that the OSD pods didn't start properly (i.e., case 3).
Signed-off-by: Ryotaro Banno <ryotaro.banno@gmail.com>