Move Field proto out of stats_log.proto to keep it clean.

Test: statsd unit test passed.

Change-Id: I31ffea40cf1b82c16bf37c706969bfb159639c7b
diff --git a/cmds/statsd/src/dimension.cpp b/cmds/statsd/src/dimension.cpp
index 8c0ae97..45b3586 100644
--- a/cmds/statsd/src/dimension.cpp
+++ b/cmds/statsd/src/dimension.cpp
@@ -17,6 +17,7 @@
 #include "Log.h"
 
 #include "frameworks/base/cmds/statsd/src/statsd_config.pb.h"
+#include "frameworks/base/cmds/statsd/src/statsd_internal.pb.h"
 #include "dimension.h"
 #include "field_util.h"