[EPH] Update expected user agent in tests

[mikeharder]

• Continuation of [EPH] Update event-hub version to 2.1.1 and make it compatible with EPH #4333
• Required to fix pipeline js - eventhubs-processor - tests

[mikeharder]

/azp run js - eventhubs-processor - tests

[azure-pipelines]

Azure Pipelines successfully started running 1 pipeline(s).

[mikeharder]

@shivangi: I think this PR should be merged as-is to unblock tests, but this code should later be improved by extracting the constant into a separate file like already done in event-hubs:

azure-sdk-for-js/sdk/eventhub/event-hubs/src/util/constants.ts

Line 7 in 8086331

export const packageJsonInfo = {

azure-sdk-for-js/sdk/eventhub/event-hubs/src/connectionContext.ts

Line 73 in ef2b4e6

const userAgent: string = `azsdk-js-azureeventhubs/${packageJsonInfo.version} (NODE-VERSION ${

azure-sdk-for-js/sdk/eventhub/event-hubs/test/client.spec.ts

Line 265 in 550f959

properties!["user-agent"].should.startWith(`azsdk-js-azureeventhubs/${packageVersion}`);

[mikeharder]

/azp run js - eventhubs-processor - tests

[azure-pipelines]

Azure Pipelines successfully started running 1 pipeline(s).