libhardware_headers export headers from libcutils

Some headers of libhardware are using headers from libcutils.

Bug: 33241851
Test: BOARD_VNDK_VERSION=current m -j successful with aosp_arm target
Change-Id: I649056285ced1cd5da4aba6a19b25e22c43c8621
diff --git a/Android.bp b/Android.bp
index f6aacd2..55b7af4 100644
--- a/Android.bp
+++ b/Android.bp
@@ -5,10 +5,12 @@
     header_libs: [
         "libaudio_system_headers",
         "libsystem_headers",
+        "libcutils_headers",
     ],
     export_header_lib_headers: [
         "libaudio_system_headers",
-        "libsystem_headers"
+        "libsystem_headers",
+        "libcutils_headers",
     ],
 
     export_include_dirs: ["include"],