Remove support code for native Core Platform API checks

Native Core Platform API checks rely on the stack unwinder. The
unwinder instance increases the zygote rss by ~4MB. We need to keep the
unwinder around to keep checks fast and not churn memory resources.

Bug: 124338141
Bug: 144502743
Bug: 149029127
Test: m & boot
Change-Id: Ia306ec6e48d7b2b330efd771348b563767973269
(cherry picked from commit 9f8ead24a13e0471a333f0776a024e970662591c)
11 files changed