Fix operator to support image with sha256 tags through env vars

[hj-johannes-lee]

Describe the bug
Operatorhub bundle can have sha256 image tags that are put through env vars. When operator controller manager gets upgraded, its operands (plugin daemonsets) should be updated to the image in the env vars. But it has not been working properly because of wrong parsing.

To Reproduce
Steps to reproduce the behavior:
Follow the part that installs olm and deploys operator using operatorhub bundle in DEVEL.md. Deploy one plugin and then upgrade the bundle with

# for example, qat plugin
kubectl apply -k deployments/operator/samples/deviceplugin_v1_qatdeviceplugin.yaml
operator-sdk run bundle-upgrade <bundle image name> -n testoperator

You will see the operator gets upgraded, but plugin remains the same.

Expected behavior
The plugin deployed before the upgrade should be upgraded together with the operator to run the image in the env vars.

Screenshots

System (please complete the following information):

• OS version: Ubuntu 24.04
• Kernel version: Linux 6.11
• Device plugins version: v0.29.0-v0.31.0
• Hardware info: SPR with QAT

Additional context