Azure expects the tags format to use a pointer to the string for the map value.
The configuration from the builder is not a pointer so when storing in the state bag for
reference in later execution we convert it when creating the StateBag.
Fixes#10012 and #10013.
* Use the MapToAzureTags helper and error check in resource group creation
* Added test case for tag values not using a pointer
* test/azure/arm: Add test to verify tags stored in state
* test/azure/arm: Add azure_tags to existing acceptance test for Linux
Test Before Fix
```
--- FAIL: TestBuilderAcc_ManagedDisk_Linux (1.81s)
panic: interface conversion: interface {} is map[string]string, not map[string]*string [recovered]
panic: interface conversion: interface {} is map[string]string, not map[string]*string
FAIL github.com/hashicorp/packer/builder/azure/arm 1.822s
```
Test After Fix
```
2020/09/29 17:23:03 ui: ==> test: Resource group has been deleted.
--- PASS: TestBuilderAcc_ManagedDisk_Linux (517.41s)
PASS
ok github.com/hashicorp/packer/builder/azure/arm 517.426s
```
Co-authored-by: Wilken Rivera <dev@wilkenrivera.com>