Logs magnification feature behavior. (1/2)

Uses the atom MagnificationUsageReported in westworld to log the
activated mode and its duration of the magnification.

The timing of logging the MagnificationUsageReported is
when the magnification feature is deactivated.

Bug: 154021596
Test: a11y CTS & unit tests
Test: make statsd_testdrive && ./out/host/linux-x86/bin/statsd_testdrive 345
Change-Id: I708e9731da23658774e462968a6b9df648b0ed19