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

fix!: [ShoppingMerchantAccounts] The type of an existing field time_zone is changed from message to string in message .google.shopping.merchant.accounts.v1beta.ListAccountIssuesRequest #13917