Revert "[CB-2226] Add spec test for FileTransfer.abort error callback"

This reverts commit 46e478f306f6aae8d550ef8d688329b14bd6a2fa.
Revert "[CB-2305] Add spec tests for InAppBrowser.insertCSS and InAppBrowser.executeScript APIs"

This reverts commit dbf631c43a76181e132a950a445e452ab44adf1e.