Revise based on Mark's comments.
diff --git a/build.yaml b/build.yaml
index 6fbc8d9..e5bec63 100644
--- a/build.yaml
+++ b/build.yaml
@@ -783,11 +783,13 @@
   - src/core/tsi/ssl_transport_security.h
   - src/core/tsi/ssl_types.h
   - src/core/tsi/transport_security.h
+  - src/core/tsi/transport_security_adapter.h
   - src/core/tsi/transport_security_interface.h
   src:
   - src/core/tsi/fake_transport_security.c
   - src/core/tsi/ssl_transport_security.c
   - src/core/tsi/transport_security.c
+  - src/core/tsi/transport_security_adapter.c
   deps:
   - gpr
   secure: true