Addressed BUG:698 - Build failing with -m POL -m PROMETHEUS -m KEYSTONE-DB

Modified file: installers/full_install_osm.sh
Edited the script to parse the following arguments with -m option
POL
PROMETHEUS
KEYSTONE-DB

Change-Id: Ia9b7d2526161494257c73dbfa58626f26c9508b6
Signed-off-by: govindappa <prabhunath.g@tataelxsi.co.in>