[Minor] fix(docker-image): Fix bugs in publishing Iceberg rest server…

… docker image (#4692)

### What changes were proposed in this pull request?

Fix the bugs about github environment for image_type

### Why are the changes needed?

it's a bug.


### Does this PR introduce _any_ user-facing change?

N/A

### How was this patch tested?

test locally.

.github/workflows/docker-image.yml

@@ -115,7 +115,7 @@ jobs:
           sudo rm -rf /usr/local/lib/android
           sudo rm -rf /opt/hostedtoolcache/CodeQL
           
-          if [[ "${image_type}" == "gravitino" || "{image_type}" == "iceberg-rest-server" ]]; then
+          if [[ "${image_type}" == "gravitino" || "${image_type}" == "iceberg-rest-server" ]]; then
             ./dev/docker/build-docker.sh --platform all --type ${image_type} --image ${image_name} --tag ${{ github.event.inputs.version }} --latest
           else
             ./dev/docker/build-docker.sh --platform all --type ${image_type} --image ${image_name} --tag "${tag_name}-${{ github.event.inputs.version }}"