Fixing several test cases

Fixed several test cases:
 * BroadcastsBricksTest
 * PlaySoundBrickTest
 * SoundRecorderTest

Jenkins Testrun:
http://catrobatgw.ist.tugraz.at:8080/job/Catroid-custom-branch-test/855/
The ProjectActivityTest failed, because the screenlock on the test device was on, so here is the single ui test:
http://catrobatgw.ist.tugraz.at:8080/job/Catroid-single-UI-test/566/