Move selinux dependencies out of header files.

Bug: http://b/27764900
Change-Id: Ib62a59edcb13054f40f514c404d32b87b14ed5f1
diff --git a/minzip/Zip.c b/minzip/Zip.c
index 0f89835..9f550f8 100644
--- a/minzip/Zip.c
+++ b/minzip/Zip.c
@@ -23,6 +23,9 @@
 #undef NDEBUG   // do this after including Log.h
 #include <assert.h>
 
+#include <selinux/label.h>
+#include <selinux/selinux.h>
+
 #define SORT_ENTRIES 1
 
 /*