Add export header lib headers to libaudiofoundation_headers.

Add libaudio_system_headers, libaudioclient_headers, libmedia_headers
to export_header_lib_headers for libaudiofoundation_headers so that
there is not needed to add header lib when using libaudiofoundation.

Test: make
Bug: 135621476
Change-Id: Iaa2c8046f9bce4b69398795e162d1ee39cece24b
Merged-In: Iaa2c8046f9bce4b69398795e162d1ee39cece24b