Update to build against libchrome-242728.

This CL updates metrics to build against libchrome-242728 and also converts
libmetrics into slotted libraries (libmetrics-180609 and libmetrics-242728).

BUG=chromium:341521
BUG=chromium:342866
CQ-DEPEND=CL:186027
CQ-DEPEND=CL:186026
CQ-DEPEND=CL:186037
CQ-DEPEND=CL:186092
CQ-DEPEND=CL:186028
CQ-DEPEND=CL:186029
CQ-DEPEND=CL:186038
CQ-DEPEND=CL:186093
CQ-DEPEND=CL:186100
CQ-DEPEND=CL:186039
TEST=Trybot run on paladin, release, and chromiumos-sdk builders.

Change-Id: I09dc3d47cfe24a22864abf217658c63493b35cba
Reviewed-on: https://chromium-review.googlesource.com/185187


Reviewed-by: Ben Chan <benchan@chromium.org>
Tested-by: Ben Chan <benchan@chromium.org>
Commit-Queue: Ben Chan <benchan@chromium.org>