Fix BackendHint missing when cloning a layer
Fix BackendHint missing when cloning a layer

Signed-off-by: Narumol Prangnawarat <69edcbdcd87555e3afc9489509030a49766559ed@arm.com>
Change-Id: I550fb59469af39f8fa3415843e973f06b18485e5

ARM-software/armnn,ARM-software/armnn,ARM-software/armnn