Add network handle to the nflog prefix for wakeups

This is useful in the system server for better attribution of wakeup
events.
The logic for encoding the data in the prefix is still maintained ad-hoc
and should be standardized in the future.

Test: Builds, boots. Manually triggering a wifi wakeup doesn't result
in anything unexpected.
Test: atest FrameworksNetTests

Bug: 265742148
Change-Id: I7ef8a606459bb9f0630f629c01d3b34643ae5319