Converting firmware_DevMode to use new FirmwareTest class.

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

1. Converted the test to use the new flat function call style.

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

Change-Id: I2bd30240a4bfc30fb5dce72de560261487b58b20
Reviewed-on: https://chromium-review.googlesource.com/200396
Reviewed-by: Wai-Hong Tam <waihong@chromium.org>
Commit-Queue: Yusuf Mohsinally <mohsinally@chromium.org>
Tested-by: Yusuf Mohsinally <mohsinally@chromium.org>
1 file changed