Fix demo usage of Storage API
Fix demo usage of Storage API

The Storage API just changed to return an AbortableOperation instead
of a Promise.  The demo did not adopt this new API at the same time.

The runtime backward compatibility provided by the Storage API was
working, so the demo was not broken.  But we should be using the API
as defined.

This was caught by a compiler upgrade.

Issue #2528

Change-Id: I2d427ffb0400739c5d2de17a06c5fd79de3d39b2

tvoli/shaka-player,shaka-project/shaka-player,tvoli/shaka-player,shaka-project/shaka-player,tvoli/shaka-player,shaka-project/shaka-player,tvoli/shaka-player,shaka-project/shaka-player