In case we have multiple top level uses statements we also
need to generate an override of implementedInterfaces() to prevent
clashes with the return types of the extended interfaces.
JIRA: MDSAL-573
Change-Id: I07ad3f6dc5a18369f0be4bdaba03c6c17072297b Signed-off-by: Tomas Cere <tomas.cere@pantheon.tech>