New-AzFunctionApp fails in non-public Azure clouds due to hardcoded endpoint values for storage connection strings

### Description

New-AzFunctionApp fails in non-public Azure clouds due to hardcoded endpoint values for storage connection strings

### Issue script & Debug output

```PowerShell
N/A
```

### Environment data

```PowerShell
N/A
```

### Module versions

```PowerShell
Az.Functions version 4.3.0
```

### Error output

```PowerShell
N/A
```