Wifi-HAL: Treat wake counter related stats from driver as optional

Earlier, all the attributes of wakestats were considered mandatory
to be present from driver. This commit addresses that wake counter
related stats to be treated as optional. If these attributes are
not present in the message from driver then it is reported as zero
instead of discarding the whole message.

Bug: 121156966
Test: Regression

CRs-Fixed: 2218700
Change-Id: I51137a5104537edae9529e2b6b62f5f07e10c67a