[POLICY] Use common secret template in brmsgw

Use common secret template in brmsgw module instead of hardcoding them in
config map.

For now creds are hardcoded but this will be remove in further commits.

Issue-ID: OOM-2342
Signed-off-by: Dominik Mizyn <d.mizyn@samsung.com>
Change-Id: Ic6ea25004d87d993b40df838dd30a71e25386b2c
3 files changed