IVGCVSW-4446 Add HardSwish EndToEnd tests

* adds convert from armnn HardSwish to Acl HardSwish
* adds EndToEnd tests for Ref, Cl and Neon

Signed-off-by: Jan Eilers <jan.eilers@arm.com>
Change-Id: If997dad783ff45d7f061254e7e30bb69d4d4d564
diff --git a/src/backends/aclCommon/ArmComputeUtils.hpp b/src/backends/aclCommon/ArmComputeUtils.hpp
index 01a5445..c3cfb5c 100644
--- a/src/backends/aclCommon/ArmComputeUtils.hpp
+++ b/src/backends/aclCommon/ArmComputeUtils.hpp
@@ -66,6 +66,7 @@
         case ActivationFunction::Square:        return AclActivationFunction::SQUARE;
         case ActivationFunction::TanH:          return AclActivationFunction::TANH;
         case ActivationFunction::Elu:           return AclActivationFunction::ELU;
+        case ActivationFunction::HardSwish:     return AclActivationFunction::HARD_SWISH;
         default:                                throw InvalidArgumentException("Unsupported activation function");
     }
 }