Use IMAGE_DIGEST in OLM template

[2uasimojo]

To make the OLM template easier to understand, replace ${REPO_DIGEST} with ${REGISTRY_IMG}@${IMAGE_DIGEST}.

IMAGE_DIGEST is supported as of APPSRE-3265.

[openshift-ci[bot]]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: 2uasimojo, lisa

The full list of commands accepted by this bot can be found here.

The pull request process is described here

Needs approval from an approver in each of these files: - ~~[OWNERS](https://github.com/openshift/aws-account-operator/blob/master/OWNERS)~~ [lisa] Approvers can indicate their approval by writing `/approve` in a comment Approvers can cancel approval by writing `/approve cancel` in a comment

[codecov-commenter]

Codecov Report

Merging #577 (6276e59) into master (e01ae9d) will decrease coverage by 0.80%. The diff coverage is n/a.

@@            Coverage Diff             @@
##           master     #577      +/-   ##
==========================================
- Coverage   13.46%   12.66%   -0.81%     
==========================================
  Files          44       45       +1     
  Lines        3774     4913    +1139     
==========================================
+ Hits          508      622     +114     
- Misses       3243     4267    +1024     
- Partials       23       24       +1     

Impacted Files	Coverage Δ
pkg/apis/aws/v1alpha1/accountclaim_types.go	8.00% <0.00%> (-0.34%)	:arrow_down:
pkg/awsclient/client.go	0.00% <0.00%> (ø)
pkg/controller/account/ec2.go	0.00% <0.00%> (ø)
pkg/controller/account/iam.go	0.00% <0.00%> (ø)
pkg/controller/utils/status.go	0.00% <0.00%> (ø)
pkg/controller/utils/conditions.go	0.00% <0.00%> (ø)
...er/awsfederatedrole/awsfederatedrole_controller.go	0.00% <0.00%> (ø)
pkg/apis/scheme/scheme.go	63.63% <0.00%> (ø)
pkg/controller/account/account_controller.go	0.49% <0.00%> (+0.10%)	:arrow_up:
pkg/controller/account/byoc.go	35.58% <0.00%> (+0.64%)	:arrow_up:
... and 3 more