Converting firmware_ShellBall to use new FirmwareTest class.

The new FirmwareTest class does not require the traditional dict of objects
that FAFTSequence required.

Note that this test does not currently work, and will not work till some
additional fixes are put into place. Doing this work to unblock removal of the
old faft classes.

1. Converted the test to use the new flat function call style.
2. Fixed doc string in control file.

BUG=chromium:371185
TEST=Manually ran this test at desk against squawks device.

Change-Id: If0a0c317ec46d08202740e98f109cd1c2cf8fccc
Reviewed-on: https://chromium-review.googlesource.com/205957
Reviewed-by: Vic Yang <victoryang@chromium.org>
Commit-Queue: Yusuf Mohsinally <mohsinally@chromium.org>
Tested-by: Yusuf Mohsinally <mohsinally@chromium.org>
2 files changed