If your calendar is a Google calendar, it's already stored by Google and therefore safe if your device is lost, stolen or dies.
If you want this as a way to restore your calendar to a prior state, how would you want it to treat changes (additions, deletions or edits) upon restore?
Without knowing WHY you want to save to Google Drive, it's hard to know whether to vote for this or not.
If your calendar is a Google calendar, it's already stored by Google and therefore safe if your device is lost, stolen or dies.
If you want this as a way to restore your calendar to a prior state, how would you want it to treat changes (additions, deletions or edits) upon restore?
Without knowing WHY you want to save to Google Drive, it's hard to know whether to vote for this or not.