This account is used by the Snaps in the Google Pub-Sub Snap Pack.
You can create an account from a Designer or Manager. In Designer, when working on pipelines, every Snap that needs an account prompts you to create a new account or use an existing account. The accounts can be created in or used from:
Your private project folder: This folder contains the pipelines that will use the account.
Your Project Space’s shared folder: This folder is accessible to all the users that belong to Project Space.
The global shared folder: This folder is accessible to all the users within an organization in the SnapLogic instance.
Drag a Google PubSub Snap to the Canvas and click the Snap to open its settings. Click the Account tab. You can now either use an existing account or create a new one.
SnapLogic organizes and displays all accounts to which you have access, sorting them by account type and location. To select an existing account:
In the Account tab, click the icon to view the accounts to which you have access, and select the account that you want to use.
Click <Save_icon>.
In the Account tab, click Add Account below the Account Reference field.
Select the Location in which you want to create the account, select the Account Type, and click Continue. The Add Account dialog window associated with the account type is displayed.
Enter the required account details.
Click Validate to verify the account, if the account type supports validation.
Click Apply to complete configuring the Google PubSub account.
You can use Manager to create accounts without associating them immediately with Pipelines.
In the left pane, browse to the project in which you want to create the account and click 
> Account > <Snap Pack Name>, followed by the appropriate account type. The Create Account dialog associated with the selected account type is displayed.
Repeat the steps numbered 3 through 5 in the Creating an account section.
Google Pub Sub Account:
This contains the properties for client id, email id, private key, private key-id, project id, and scopes(read-only). This account is used by Pubsub Snaps for getting the ServiceAccountCredentials.
Note:
Needs to provide snaplogic.com as an authorized domain name in the consent screen for the project in order to give access to snap logic.
Create a Service account in google pub-sub and download the related JSON file. The values for this account will be in the downloaded JSON file.
Click Create, then select Google Pub-Sub
Provide an account label.
Provide Client Id, EmailId
Supply Private Key
Provide Private Key Id
Provide Project Id and Scope
Click Apply.
Note: This account is used by all the snaps from this custom snap pack for getting access token information.