Override RESTIC_REPOSITORY in ReplicationSource

[johnuopini]

Describe the feature you'd like to have.
I am using 1Password operator to generate the secret so adding a different RESTIC_REPOSITORY depending on the PVC i am trying to backup is not easy as i cannot patch the secret generated by the operator. It would be great if we could override RESTIC_REPOSITORY in ReplicationSource so the secret could be reused on different PVCs

What is the value to the end user? (why is it a priority?)
User could reuse the same secret to backup different PVC, user could use 1Password operator to store AWS KEY and RESTIC KEY

How will we know we have a good solution? (acceptance criteria)
Overriding this in ReplicaSource should be trivial