[CI] generate antrea manifests in hw-offload CI with a custom image

Following antrea-io#1617, the default image name in the antrea.yml file changed
to use the harbor image. Although the patch includes a change in the
make file to change the image name correctly in case the image was
built, the hw-offload CI uses `docker build` to build the image, and
this made it so that the CI would not use the image it was building,
but the upstream latest image.

This patch fixes that by building the antrea manifests with the image
name being the same as the one that was built.

ci/jenkins/mellanox/scripts/start_ci.sh

@@ -94,9 +94,16 @@ EOF
     if [[ -z "${ANTREA_CNI_PR}${ANTREA_CNI_BRANCH}" ]];then
         change_image_name $ANTREA_CNI_HARBOR_IMAGE antrea/antrea-ubuntu
     fi
+
+    bash $WORKSPACE/antrea-cni/hack/generate-manifest.sh --dev-image "antrea/antrea-ubuntu" > $ARTIFACTS/antrea.yml
+    let status=status+$?
+    if [ "$status" != 0 ]; then
+        echo "ERROR: Failed to generate antrea manifest!"
+        return $status
+    fi
 
     if [[ -z "$(grep hw-offload $WORKSPACE/antrea-cni/build/yamls/antrea.yml)" ]];then
-        sed -i '/start_ovs/a\        - --hw-offload' $WORKSPACE/antrea-cni/build/yamls/antrea.yml
+        sed -i '/start_ovs/a\        - --hw-offload' $ARTIFACTS/antrea.yml
     fi
 
     cat > $ARTIFACTS/antrea-net.yaml <<EOF
@@ -158,7 +165,7 @@ kubectl create -f $ARTIFACTS/antrea-net.yaml
 kubectl create -f $ARTIFACTS/configMap.yaml
 kubectl create -f $(ls -l $WORKSPACE/sriov-network-device-plugin/deployments/*/sriovdp-daemonset.yaml|tail -n1|awk '{print $NF}')
 
-kubectl create -f $WORKSPACE/antrea-cni/build/yamls/antrea.yml
+kubectl create -f $ARTIFACTS/antrea.yml
 
 cp $ARTIFACTS/antrea-net.yaml $(ls -l $WORKSPACE/sriov-network-device-plugin/deployments/*/sriovdp-daemonset.yaml|tail -n1|awk '{print $NF}') $ARTIFACTS/
 echo "All code in $WORKSPACE"