Return error Status from BpfHandler::initPrograms()

Instead of logging and aborting from the BpfHandler::initPrograms(),
return a Status object with an error message. The caller
NetdUpdatable::libnetd_updatable_init() will log the message. Netd
main() will exit and restart.

Bug: 312094533
Test: m
Change-Id: I6717da871a9a53357ac895709ea0094c089e7bbd