BUG-869: minor changes to improve code readability in TypeDefinitionAwareCodec

 - String.format should use %n rather than \n
 - removed redundant call to String.toString on known non-null object

Change-Id: Iac2506041184852c1e1e12bab787d1eefef1358b
Signed-off-by: Martin Vitez <mvitez@cisco.com>
Merge "BUG-869: minor changes to improve code readability in TypeDefinitionAwareCodec"