The viewer logs in to Third-Party Entitlement Server making the SignInWithCredentials call to get the auth token and sends it to Adobe entitlement service. In this example, the entitlement server URL is https://dps.tukker.org.
The call that sends it to Adobe server is the second one in the iOS screenshot and the third one on Android. It accesses the address https://subscriber.adobepublish.com and the URL contains the integratorId and the accountId. Its response should create a unique ticket which is used further. Now, the device is marked as logged in.
The call to the http://edge.adobe-dcfs.com extracts the list of the productId that are created in the database for that specific account. It contains the accountId, sessionId, viewerVersion, and other details.
The last call from the Figure 1. is the one that differs on iOS than Android. That call is the one that update the library for the new logged in user. The response of this call contains the list of productIds that the user is entitled to. This is the call that needs to be done manually on Android and that is included in the sample code attached.