Retrieve ad groups and their performance metrics for a specified date range.
Args: customer_id: The Google Ads customer ID login_customer_id: Optional manager account ID campaign_id: Optional filter by campaign ID start_date (str): Start date for the data range (YYYY-MM-DD). Defaults to 30 days ago. end_date (str): End date for the data range (YYYY-MM-DD). Defaults to today. limit: Maximum number of records to return
oauth2_token: OAuth2 token for authentication
Returns: List of ad groups with performance metrics
The access token received from the authorization server in the OAuth 2.0 flow.