[Documentation]: Grammar error in SyncInitializer comment

### Is there an existing issue for this?

- [x] I have searched the existing issues

### Page URL (type "NEW" for a new page suggestion)

https://github.com/android/nowinandroid/blob/main/sync/work/src/main/kotlin/com/google/samples/apps/nowinandroid/sync/initializers/SyncInitializer.kt

### What's the documentation problem or suggestion?

There is a small grammar issue in the `Sync.initialize` comment.

Current text:

`This method is initializes sync, the process that keeps the app's data current.`

Suggested text:

`This method initializes sync, the process that keeps the app's data current.`

This is a comment-only documentation cleanup and does not change app behavior.

### Code of Conduct

- [x] I agree to follow this project's Code of Conduct

Open sync/work/src/main/kotlin/com/google/samples/apps/nowinandroid/sync/initializers/SyncInitializer.kt and locate the Sync.initialize comment. Compare the current sentence with the suggested wording in the issue, then verify the comment contains the corrected grammar and that no behavioral code changed.

Written by the indexing model from the issue text.