Replaced sprintf with snprintf in the sdk to avoid potential buffer overflows

Replaced sprintf with snprintf in the sdk to avoid potential buffer overflows

Defect IOT-123 stated that unsafe API sprintf was previously used in SDK and
the recommendation was given to use snprintf rather than sprintf in order to
avoid buffer overflow.

As a result sprintf was replaced with safer snprintf in multiple sdk files

Change-Id: Ic739506f160176aaeb78927745ea67e61c1c0066
Signed-off-by: Yuliya Kamatkova <yuliya.kamatkova@intel.com>