Fix some UI Tests

UploadDialogTest.testUploadDialog is failing from time to time - an additional WaitForActivity could solve the problem!
errormessage from Jenkins: http://catrobatgw.ist.tugraz.at:8080/job/Catroid-no-emma/59/testReport/org.catrobat.catroid.uitest.ui.dialog/UploadDialogTest/testUploadDialog/

testrun of this testclass: http://catrobatgw.ist.tugraz.at:8080/job/Catroid-single-UI-test/910/console
at least the specific error did not occur any more.


Another test was failing for the last weeks: http://catrobatgw.ist.tugraz.at:8080/job/Catroid-no-emma/59/testReport/org.catrobat.catroid.uitest.ui.fragment/LookFragmentTest/testEditImageInPaintroidThreeWorkflows/history/?
testrun of this specific test with quickfix: http://catrobatgw.ist.tugraz.at:8080/job/Catroid-single-UI-test/912/console