Refactor ui tests

Start to refactor testcases to run on the Emulator rather than on the Device as mentioned in #704. The remaing ```@Device```  annotations will be part of further investigation.

Jenkins testrun: https://jenkins.catrob.at/job/Catroid-Multi-Job-Custom-Branch/526/

Failed tests:
* org.catrobat.catroid.uitest.ui.activity.MyProjectsActivityTest.testProjectDetailsLastAccess (topic of #718)
* org.catrobat.catroid.uitest.ui.dialog.UploadDialogTest.testUploadingProjectDescriptionDefaultValue (reverted change for this pull request, see c0986eb and [testrun](https://jenkins.catrob.at/job/Catroid-single-UI-device/128/))