hcl2_upgrade doesn't properly convert `plan_info` of azure builder

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#### Overview of the Issue

When converting packer azure builder from json to hcl format using `hcl2_upgrade` command the plan_info isn't properly converted to hcl format :
```
"type": "azure-arm",
"plan_info": {
"plan_name": "centos-stream-8-0-free",
"plan_product": "centos-stream-8-0-free",
"plan_publisher": "eurolinuxspzoo1620639373013"
},
```
into hcl is this
```
plan_info = {
plan_name = "centos-stream-8-0-free"
plan_product = "centos-stream-8-0-free"
plan_publisher = "eurolinuxspzoo1620639373013"
}
```
but instead should be this
```
plan_info {
plan_name = "centos-stream-8-0-free"
plan_product = "centos-stream-8-0-free"
plan_publisher = "eurolinuxspzoo1620639373013"
}
```

I think previously people have experienced this issue as [stated here](https://github.com/hashicorp/packer/issues/10462)

I highly urge to please to please find a robust method for hcl2_upgrade command as I think same type of problem occurred with `shared_image_gallery` tag [for azure](https://github.com/hashicorp/packer/issues/11942)

#### Reproduction Steps

Steps to reproduce this issue

### Packer version
`Packer v1.8.5`

### Simplified Packer Template

If the file is longer than a few dozen lines, please include the URL to the
[gist](https://gist.github.com/) of the log or use the [Github detailed
format](https://gist.github.com/ericclemmons/b146fe5da72ca1f706b2ef72a20ac39d)
instead of posting it directly in the issue.

### Operating system and Environment details

OS, Architecture, and any other information you can provide about the
environment.

### Log Fragments and crash.log files

Include appropriate log fragments. If the log is longer than a few dozen lines,
please include the URL to the [gist](https://gist.github.com/) of the log or
use the [Github detailed format](https://gist.github.com/ericclemmons/b146fe5da72ca1f706b2ef72a20ac39d) instead of posting it directly in the issue.

Set the env var `PACKER_LOG=1` for maximum log detail.