DataGrid: Narrator does not announce AutomationProperties.HelpText

### Description

Narrator does not announce AutomationProperties.HelpText for the DataGrid.

The help text should be announced from DataGrid when it it assigned to them:

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### Reproduction Steps

1. Turn on Narrator
2. Give focus on the DataGrid

### Expected behavior

Help text should be read aloud from DataGrid

### Actual behavior

Hear Narrator announce the DataGrid, but not the help text associated with the DataGrid

### Regression?

_No response_

### Known Workarounds

_No response_

### Impact

_No response_

### Configuration

_No response_

### Other information

_No response_