Unable to add a variable in multi-line edit mode

### Severity

P1 - Critical (Blocking production)

### Describe the Bug with repro steps

Hi,

I just noticed an issue with picking a variable in logic app, in case my expression is multi-line.
I can add it with no issue if my expression has only one line, but it stops working if I add even a single line-break character.

### What type of Logic App Is this happening in?

Consumption (Portal)

### Are you experiencing a regression?

_No response_

### Which operating system are you using?

Windows

### Did you refer to the TSG before filing this issue? https://aka.ms/lauxtsg

Yes

### Workflow JSON

```json

```

### Screenshots or Videos

_No response_

### Environment

Browser: Firefox 147.0.4 (64-bit)

### Additional context

_No response_

No source file or test is named. Start by reproducing the issue in the Consumption Portal with a multiline expression and variable picker in Firefox; done means variables can be added successfully when the expression contains a line break.

Written by the indexing model from the issue text.