Stop copying the pre-pulled uncompressed machine disk into the individual test dir. The machine pull code already makes a copy of the disk into the test's HOMEDIR/.local/share/containers/podman/machine, and works off that copy.
Before the change: TESTDIR/<image> is copied to TESTDIR/podman_test/<image> by the test, and then podman machine copies the image to TESTDIR/podman_test/.local/share/containers/podman/machine/provider/<image>
After the change: TESTDIR/<image> is copied to TESTDIR/podman_test/.local/share/containers/podman/machine/provider/<image> by podman machine
The image that is actually run is at TESTDIR/podman_test/.local/share/containers/podman/machine/provider/<image> in both instances.
Signed-off-by: Ashley Cui <acui@redhat.com>