[COMMON] Allow special characters in postgress passwords

[COMMON] Allow special characters in postgress passwords

Postgres image that we are currently using uses sed to replace
passwords placeholders with their actual values at startup time.
This apprach is very fragile and leads to issues if & happens to be a
part of password as it has a special meaning in sed.

To fix this issue let's just extract the setup.sql file from the
container and process it on our own in init container using envsubst
and then mount it to the main container to be used.

Issue-ID: OOM-2317
Signed-off-by: Krzysztof Opasiak <k.opasiak@samsung.com>
Change-Id: Ifd51d8f0af0099958caa209185fb7a87a0480bd2