labstation: pass arguments to fission processes

When servod.conf forks into servod_core and servod_data, it currently
only passes the PORT argument. This causes other arguments passed
on the command line, specifically REC_MODE, to be dropped and not passed
into the environment of the underlying fission jobs. This commit passes all
relevant parameters directly to the subjobs so that recovery mode works
correctly under fission.

BUG=b:498002328
TEST=None

Change-Id: I3dac9a74faecd8ea8c12e56ae33926123bfe61c2
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/labstation/+/7713286
Commit-Queue: Keith Haddow <haddowk@chromium.org>
Tested-by: Keith Haddow <haddowk@chromium.org>
Reviewed-by: Garry Wang <xianuowang@chromium.org>
Auto-Submit: Keith Haddow <haddowk@chromium.org>