I installed the Kotlin plugin into my app (v. v1.1.1-release-Studio2.2-1) and then selected "Configure Kotlin in Project" I selected compiler and runtime version
The split of kotlin-stdlib into kotlin-stdlib-jre7 and kotlin-stdlib-jre8 was only introduced with Kotlin 1.1, that's why the dependency cannot be resolved, the package version simply does not exist.
It looks like the update to your project files failed at some point and set the Kotlin version to 1.0.7. If this is a new project and there's nothing holding you back from using 1.1.1, I'd switch to that. Your problem should be gone after doing this.