Writes power mode changed messages to kernel log for Cuttlefish.

This is ingested by the Cuttlefish kernel log handler and passed to the
WebRTC app.

Test: Use with foldable multi-display cuttlefish
Bug: 201451003
Change-Id: I13bdba5400e2630380e2e504efef92f714de844c
Merged-In: I13bdba5400e2630380e2e504efef92f714de844c