Stop building against core_platform where possible

This is not a stable API surface, so modules shouldn't be building
against it. Compiling against core_platform also disables link-checking,
which can hide other problems.

Bug: 137191822
Test: m
Change-Id: I7ce7dad8c02b094c565daf8c178bc6f89bb610ef
Merged-In: I7ce7dad8c02b094c565daf8c178bc6f89bb610ef
(cherry picked from commit 791551a7)