Rename libbpf to libbpf_bcc

This is to prevent a name collision with "upstream"
libbpf (external/libbpf) which is built using the same name.

Bug: 203823368
Test: build cuttlefish
Signed-off-by: Connor O'Brien <connoro@google.com>
Change-Id: I8fa2b21d331ecdeabd0e0a1a9f495f29ff967623