[googlechat] Loose of cards v2 content

When specifying this card v2 content:

```yaml
- sections:
- widgets:
- textParagraph:
textSyntax: "MARKDOWN"
text: "❗Application **[my-app](https://argocd.local/applications/my-app)** on **MyEnv** has degraded."
- columns:
columnItems:
- widgets:
- decoratedText:
topLabelText:
textSyntax: "MARKDOWN"
text: "*Health Status*"
text: "Degraded"
- widgets:
- decoratedText:
topLabelText:
textSyntax: "MARKDOWN"
text: "*Repository*"
contentText:
textSyntax: "MARKDOWN"
text: "https://github.com/loganmzz/my-repository"
```

The resulting JSON sent to Google Chat endpoint is:

```json
{
"text": "",
"cardsV2": [
{
"card": {
"sections": [
{
"widgets": [
{
"textParagraph": {
"text": "Application **[my-app](https://argocd.local/applications/my-app)** on **MyEnv** has degraded."
}
},
{
"columns": {
"columnItems": [
{
"widgets": [
{
"decoratedText": {
"text": "Degraded"
}
}
]
},
{
"widgets": [
{
"decoratedText": {}
}
]
}
]
}
}
]
}
]
},
"cardId": "068cbc4d-3520-4e59-ba32-86a57ce873d4"
}
]
}
```

Reproduce the supplied Google Chat cards v2 YAML and inspect the JSON sent to the Google Chat endpoint. Compare the lost textSyntax, topLabelText, and contentText fields with the input, then verify that the resulting cardsV2 JSON preserves the card content shown in the report.

Written by the indexing model from the issue text.