Make sure originalDimensions are available before use

Before applying default size based on originalDimensions, make sure
these are available through the scalable call. The image will be
marked as default size, but the presentation will depend on whether
or not we have the defaultDimensions from the API.

Bug: 65239
Change-Id: I41b30498713e969bd24ef0ad3e9a074c6ffcdc3b