make bpf_headers visible to libclat

Needed because ClatdController and clatd binary are moved
into apex. libclat is used for accessing BPF map.

Bug: 212345928
Test: manual test
    1. Connect to ipv6-only wifi.
    2. Try IPv4 traffic.
       $ ping 8.8.8.8
Change-Id: If3fb00e12ef365ccf3ac782c4e6ecbfd01d2dd4c
1 file changed
tree: e416021671cf4588a0acd88a28c8900974ad3d77
  1. client-libs/
  2. common/
  3. .gitignore
  4. OWNERS
  5. PREUPLOAD.cfg
  6. TEST_MAPPING