Log launcher settings whenever launcher layout is logged using pull atom.

* Whenever launcher setting is changed, only log the changed setting instead of all

Bug: 181703659
Test: wwdebug && wwlogcat AND statsd_testdrive 10108

Change-Id: I9c6b7a17d653038a91f885df455e5ebbb401b49a
Merged-In: I9c6b7a17d653038a91f885df455e5ebbb401b49a
(cherry picked from commit f7ebfb9a)