Add initialization of pixel data in intrapred_test
Add initialization of pixel data in intrapred_test

BUG=aomedia:995

Change-Id: Ic320e5de9b0c7d320b0f6dddce93f1445be61234

GrokImageCompression/aom,GrokImageCompression/aom,GrokImageCompression/aom,GrokImageCompression/aom,GrokImageCompression/aom,GrokImageCompression/aom