Whole static link libasync_safe to libbacktrace.a

When libbacktrace.a is statically lined to somewhere, that library had
to add libasync_safe.a to static_libs because libbacktrace.a has
references to libasync_safe.a. But libbacktace depending on
libasync_safe is an implementation detail of libbacktrace, and therefore
its client shouldn't be affected by it.

Fixing this by doing the whole static link to libasync_safe to
libbacktrace.a so that the former is included in libbacktrace.a

Exempt-From-Owner-Approval: cherry-pick rvc-dev

Bug: 149569129
Test: m
Merged-In: If7366a240bc945dda9944fe7c111e10d328165bb
(cherry picked from commit 7c8e2b247d2411d76196dc8a56656d39fe40214e)
Change-Id: If7366a240bc945dda9944fe7c111e10d328165bb
1 file changed