Update terminology on exercise 07_Cloud_Ready_Quickstart

The content under Step 1 https://github.com/adobe/aem-enablement/tree/master/AEMAsACloudService/07_Cloud_Ready_Quickstart#lesson-context is not updated to the AEM SDK terminology as it is used on the official help section: https://docs.adobe.com/content/help/en/experience-manager-learn/cloud-service/local-development-environment-set-up/aem-runtime.html#download-the-aem-as-a-cloud-service-sdk
This might lead to confusion in the wording and give the idea that here are different quickstarts available.