generate_projects.sh and also add config.h header so that gcc4.4 can recognize nullptr

BUILD

@@ -1438,6 +1438,7 @@ cc_library(
     "src/cpp/common/channel_filter.h",
     "src/cpp/server/dynamic_thread_pool.h",
     "src/cpp/server/thread_pool_interface.h",
+    "src/cpp/thread_manager/thread_manager.h",
     "src/cpp/client/cronet_credentials.cc",
     "src/cpp/client/insecure_credentials.cc",
     "src/cpp/common/insecure_create_auth_context.cc",
@@ -1462,6 +1463,7 @@ cc_library(
     "src/cpp/server/server_context.cc",
     "src/cpp/server/server_credentials.cc",
     "src/cpp/server/server_posix.cc",
+    "src/cpp/thread_manager/thread_manager.cc",
     "src/cpp/util/byte_buffer_cc.cc",
     "src/cpp/util/slice_cc.cc",
     "src/cpp/util/status.cc",

CMakeLists.txt

@@ -1203,6 +1203,7 @@ add_library(grpc++_cronet
   src/cpp/server/server_context.cc
   src/cpp/server/server_credentials.cc
   src/cpp/server/server_posix.cc
+  src/cpp/thread_manager/thread_manager.cc
   src/cpp/util/byte_buffer_cc.cc
   src/cpp/util/slice_cc.cc
   src/cpp/util/status.cc

Makefile

@@ -3842,6 +3842,7 @@ LIBGRPC++_CRONET_SRC = \
     src/cpp/server/server_context.cc \
     src/cpp/server/server_credentials.cc \
     src/cpp/server/server_posix.cc \
+    src/cpp/thread_manager/thread_manager.cc \
     src/cpp/util/byte_buffer_cc.cc \
     src/cpp/util/slice_cc.cc \
     src/cpp/util/status.cc \

src/cpp/thread_manager/thread_manager.h

@@ -39,6 +39,7 @@
 
 #include <grpc++/impl/sync.h>
 #include <grpc++/impl/thd.h>
+#include <grpc++/support/config.h>
 
 namespace grpc {