CLOUDSTACK-1243: Add @Inject to fix NPE in AccountManagerImpl

Signed-off-by: Rohit Yadav <bhaisaab@apache.org>
(cherry picked from commit bd034e0b9f471ca1d0c3a18e135926380dc76e1c)

Signed-off-by: Rohit Yadav <bhaisaab@apache.org>