The test worked fine on CI since they are run with a clean profile.
When tests were run in a normal browser profile manually, tests
'draft creation/cancelation' and 'draft saving/editing' failed
alternately because of local storage use for saving draft comments.
Since these tests do not test local storage (yet), we can just create
a stub for 'gr-storage#getDraftComment' which simulates a clean state.
Change-Id: Ibb63be4f1c395d47e0022f63d0d2ba0a7c87b137
9b8b237431