Skip duplicates devices

This also adds testutils module to the intellij project to fix the
project setup.

Change-Id: I40bb9a8b457a3e12309d28f4f8c386e1f51c0efc

• .idea/modules.xml[diff]
• sdkmanager/sdkuilib/sdkuilib.iml[diff]
• sdkmanager/sdkuilib/src/main/java/com/android/sdkuilib/internal/repository/ui/DeviceManagerPage.java[diff]
• sdkmanager/sdkuilib/src/main/java/com/android/sdkuilib/internal/widgets/AvdCreationPresenter.java[diff]
• sdkmanager/sdkuilib/src/main/java/com/android/sdkuilib/internal/widgets/DeviceCreationDialog.java[diff]