Changed Dockerfile to use 0.2.1-Helium-SR1 instead of 0.2.0-Helium

Change-Id: I129b97908f239a5ced78bab23ad4365f8d20736a
Signed-off-by: Charalampos Kaidos <ckaidos@intracom-telecom.com>
(cherry picked from commit 8a34a3523e925a3f6ff45b80717d49ac1e7b109d)