[SB Refactor] Listen to the WIFI_STATE_CHANGED_ACTION broadcasts and
re-fetch `isWifiEnabled` whenever it happens.

Bug: 238425913
Test: manual: Go into airplane mode and verify that we get logs for the
WIFI_STATE_CHANGED_ACTION intent and for `enabled` being updated; leave
airplane mode and verify the same
Test: statusbar.pipeline tests

Change-Id: I1eba794e98a288683bc4cfe0405a98c48a2b2c03
4 files changed