Add BRANCH as Docker build arg

Add BRANCH as Docker build arg

It conforms with the prerequisite of the current releng Docker script.
BRANCH can be considered as useless because releng already clones the
right git branch.

It's a temporarily solution before modifying a script used by lots of
OPNFV projects.

Conflicts:
    docker/components/Dockerfile
    docker/healthcheck/Dockerfile

Change-Id: I585d7a79a9ebaeaffd69af1da1731c44e131f6b5
Signed-off-by: Cédric Ollivier <cedric.ollivier@orange.com>
(cherry picked from commit 9e72ad1edd88aada55a0328cd72d4941c4e6fc60)