Add EC and Firmware Versions to the Omaha Response.

This CL adds 2 additional utils methods to get the version for both the
fw and ec versions. I've added a unittest to verify these work and piped
in the values into the omaha response.

BUG=chromium:219871
TEST=Unittests + on device

Change-Id: Iadf70fff858988f52797d94bcdb062bb2482bbf3
Reviewed-on: https://gerrit.chromium.org/gerrit/49713
Commit-Queue: Chris Sosa <sosa@chromium.org>
Reviewed-by: Chris Sosa <sosa@chromium.org>
Tested-by: Chris Sosa <sosa@chromium.org>
diff --git a/omaha_request_action.cc b/omaha_request_action.cc
index c28e0d6..15d3188 100644
--- a/omaha_request_action.cc
+++ b/omaha_request_action.cc
@@ -209,6 +209,8 @@
                 "board=\"" + XmlEncode(params->os_board()) + "\" " +
                 "hardware_class=\"" + XmlEncode(params->hwid()) + "\" " +
                 "delta_okay=\"" + delta_okay_str + "\" "
+                "fw_version=\"" + XmlEncode(params->fw_version()) + "\" " +
+                "ec_version=\"" + XmlEncode(params->ec_version()) + "\" " +
                 ">\n" +
                    app_body +
       "    </app>\n";