Libziparchive: Export headers in defaults

libziparchive-host needs to include the headers correctly, too.

Bug: 37342627
Test: mmma system/core/libziparchive
Change-Id: I88a6d38ff9e494273040f9b913c71bccdda117ad
diff --git a/libziparchive/Android.bp b/libziparchive/Android.bp
index 84a9a2f..333835c 100644
--- a/libziparchive/Android.bp
+++ b/libziparchive/Android.bp
@@ -50,6 +50,8 @@
         "libbase",
         "liblog",
     ],
+
+    export_include_dirs: ["include"],
 }
 
 cc_library {
@@ -65,7 +67,6 @@
         "liblog",
         "libbase",
     ],
-    export_include_dirs: ["include"],
     target: {
         android: {
             shared_libs: [