Fix swagger and improve exception handling

1) Swagger was getting generated in a different format
due to a serialization isue. It is fixed.
2) Improved exception handling by taking care of any exceptions
that could occur in and around database operations.
3) AAF enabling/disabling was done using spring profiles.
This is changed to using parameters, as it is more easier to configure
in an OOM helm chart deployment

Change-Id: If1bee01379ba5c4efac29822662896d8aa883fc8
Issue-ID: POLICY-3975
Signed-off-by: a.sreekumar <ajith.sreekumar@bell.ca>