flag test.o bpf program as being test only

Bug: 254543135
Signed-off-by: Maciej Żenczykowski <maze@google.com>
Change-Id: I8ee7b0a552510baabb7c29d94521291b8b526692
diff --git a/bpf_progs/test.c b/bpf_progs/test.c
index d42205f..c11c358 100644
--- a/bpf_progs/test.c
+++ b/bpf_progs/test.c
@@ -40,6 +40,10 @@
 #define TETHERING_GID AID_NETWORK_STACK
 #endif
 
+// This is non production code, only used for testing
+// Needed because the bitmap array definition is non-kosher for pre-T OS devices.
+#define THIS_BPF_PROGRAM_IS_FOR_TEST_PURPOSES_ONLY
+
 #include "bpf_helpers.h"
 #include "bpf_net_helpers.h"
 #include "bpf_tethering.h"