BlobImageCache: Read cache files from same location they are stored.

[OddSkancke]

This change makes sure that BlobImageCache's GetAsync() attempts to find cached files in the same location they are written by SetAsync().

[vnbaaij]

Hi,
As I do not work for nor with Optimizely anymore, I have no means of testing this change. Before I merge this and create a new package, I need to be sure that this change does not break anything. Can you supply test results that show this is working?

[OddSkancke]

Hi, As I do not work for nor with Optimizely anymore, I have no means of testing this change. Before I merge this and create a new package, I need to be sure that this change does not break anything. Can you supply test results that show this is working?

Hi. Yes I will add some stuff to the Alloy sample to show it works as soon as possible. It might take a couple of days as I am out of office atm. Thanks for replying :)