IVGCVSW-4920 Invalid Negative Stride fix
IVGCVSW-4920 Invalid Negative Stride fix

 * Add check for negative stride with ShrinkAxisMask

Signed-off-by: Ryan OShea <78edf9889e9e5db3b98905d7b2666c47635de0f0@arm.com>
Change-Id: I69ecd2915d94278d6313d8279361c4dc675adb74

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