WifiNativeInterfaceMgmt: Handle hostapd death

Also, removed the error being returned from WificondControl,
SupplicantStaIfaceHal & HostapdHal death registration. This was needed
previously because multiple modules were alternatively registering for
these (WifiStaterMachine, SoftApManager, etc). But, now that there is
only one entity managing it, we don't need this error checking.

Bug: 72390244
Test: Unit tests
Test: Toggled softap multiple times
Change-Id: I67f65b721077bee131851be22b27143c0b072191