Properly specify dependences on alarm.h in build.yaml
diff --git a/Makefile b/Makefile
index be76014..e591938 100644
--- a/Makefile
+++ b/Makefile
@@ -2969,6 +2969,7 @@
     src/cpp/codegen/grpc_library.cc \
 
 PUBLIC_HEADERS_CXX += \
+    include/grpc++/alarm.h \
     include/grpc++/channel.h \
     include/grpc++/client_context.h \
     include/grpc++/completion_queue.h \
@@ -3248,6 +3249,7 @@
     src/cpp/codegen/grpc_library.cc \
 
 PUBLIC_HEADERS_CXX += \
+    include/grpc++/alarm.h \
     include/grpc++/channel.h \
     include/grpc++/client_context.h \
     include/grpc++/completion_queue.h \