libselinux: be strict about what symbols we export

Make sure shared libraries we create export only the minimum number of
symbols, and not a bit more. We want to be careful what SELinux APIs we
(directly or indirectly) expose to other processes.

Test: Android compiles. Link time restrictions only.
Change-Id: Ia6d1788cd944b46f1e97f621f4466fb8ada29191
2 files changed