Somebody in StackOverFlow finally helped me to make it work: https://stackoverflow.com/questions/53624376/eacces-permission-denied-in-travis-ci-android-emulator
The thing was that Android Studio adds an aditional parameter (-c 1000M) to create a SDCard when creating an emulator, that’s why in my PC the tests ran successfully. When i added that parameter in the Travis CI commands it worked! Maybe you could add that extra parameter to the Travis CI Page, where you show an example of creating an emulator, because i think most of the people will assume that it will include a SDCard. In my case i just assigned a 100 MB SDCard (-c 100M). This is my final .travis.yml: https://github.com/GabrielBB/Android-CutOut/blob/master/.travis.yml