improve screenshot tests, run in different languages, test more Fragments/Activities

app/build.gradle

...st/java/se/leap/bitmaskclient/base/ProviderSetupTest.java

...oidTest/java/se/leap/bitmaskclient/base/VpnStartTest.java

...Test/java/se/leap/bitmaskclient/suite/ScreenshotTest.java

app/src/androidTest/java/utils/CustomInteractions.java

app/src/androidTest/java/utils/CustomMatchers.java

app/src/androidTest/java/utils/CustomViewActions.java

...ain/java/se/leap/bitmaskclient/base/views/MainButton.java

...java/se/leap/bitmaskclient/testutils/TestSetupHelper.java

fastlane/Screengrabfile