fix!: [google-shopping-merchant-accounts] The type of an existing field time_zone is changed from message to string in message .google.shopping.merchant.accounts.v1beta.ListAccountIssuesRequest

fix!: [google-shopping-merchant-accounts] The type of an existing field time_zone is changed from message to string in message .google.shopping.merchant.accounts.v1beta.ListAccountIssuesRequest #6915