Explicitly include libhardware_header for vendors

Summary: This seems to  be not implicit when building vendor, so it's now necessary to explicitly include.

Test: Succesful build on master

Change-Id: Ie9720a3ae4c9f94210bc34c60d14756c7d0cf56f
Signed-off-by: Abdelrahman Daim <adaim@meta.com>