Change export_include_dirs into export_header_lib_headers

Remove the duplicated information that headers for libbinder is in the
'include' dir.

Test: m -j
Change-Id: I5527c2709ff9d3a996c619f973345e61407cd3f0
diff --git a/libs/binder/Android.bp b/libs/binder/Android.bp
index 204fdb5..509b0b1 100644
--- a/libs/binder/Android.bp
+++ b/libs/binder/Android.bp
@@ -74,13 +74,18 @@
         "libcutils",
         "libutils",
     ],
+
+    header_libs: [
+        "libbinder_headers",
+    ],
+
     export_shared_lib_headers: [
         "libbase",
         "libutils",
     ],
 
-    export_include_dirs: [
-        "include",
+    export_header_lib_headers: [
+        "libbinder_headers",
     ],
 
     clang: true,