Toughen the path resolution of Coverage.profdata and the desired product.
Toughen the path resolution of Coverage.profdata and the desired product.

Before this change we assumed that Coverage.profdata and the desired product would live in specific directories.

After this change we'll search for both files each time the build initiaties. This resolves a bug affecting Xcode 7.3 and later due to changes in build paths from Xcode 7.2 to 7.3.

Closes https://github.com/google/arc-xcode-test-engine/issues/2.

shepting/arc-xcode-test-engine,google/arc-xcode-test-engine