Currently, json array macros are passing the outer "container" struct
to the Z_JSON_ELEMENT_DESCR macro, causing the alignment to be calculated
from the outer struct which may be incorrect. Fix this by using the
biggest shift from the nested objects to calculate the alignment as the
struct size is calculated based on the biggest alignment of it's members.
Signed-off-by: Mykyta Poturai <mykyta_poturai@epam.com>