GR-STORAGE did not fail gracefully when the quota is exceeded (DOM
exception 22). The test configuration for Safari disables localStorage
and throws a quota exceeded exception every time that
`window.localStorage.setItem` was called.
With this change GR-STORAGE cleanly disables itself when the quota is
exceeded and the tests are updated to not depend on a nonzero quota in
the browser.
Bug: Issue 5799
Change-Id: I23eac096b93eaa16b185248d23efe98671cfce48
66e9687afc