Update interface.ts to fix Angular 19 deploy

[quedicesebas]

Fix for Angular19, should prevent 'Expected array, received object' error.

[google-cla]

Thanks for your pull request! It looks like this may be your first contribution to a Google open source project. Before we can look at your pull request, you'll need to sign a Contributor License Agreement (CLA).

View this failed invocation of the CLA check for more information.

For the most up to date status, view the checks section at the bottom of the pull request.

[Yuangwang]

Copying from my comment in #277 here for visibility

For anyone running into this issue. We'll keep y'all posted on when this fix goes live. Until then please give this workaround a try:

Step 1:
In your project run npm install @apphosting/[email protected], this will install the latest adapter with this fix merged in.
After running that please verify that you see @apphosting/adapter-angular": "^17.2.11 in your package.json. Its important that the version is 17.2.11 since this fix is released with that version.

Step 2:
Add this additional line in your package.json scripts: "apphosting:build": "FRAMEWORK_VERSION=${YOUR_ANGULAR_VERSION} apphosting-adapter-angular-build"

Step 3:
Commit these changes to github and kickoff a new rollout