The data files for any given test will be in the same directory as the
source with a file name that matches *.dat. To make these available to
tests running remotely (such as over adb or ssh), copy them into the
test's remote working directory.
Note that we will perform more copies than we actually need. The data
files in the directory may only be used by one of the tests, but will
be copied for all tests in the same directory.
This patch also moves the remote test binary into the working
directory (previously it was only invoked from the working directory
rather than existing in it).