Create stats buffer in logd.

Test: Ran the existing tests in logd, liblog and logcat. Confirmed that the liblog tests are already failing at head. Also that logcat test fails at head.
Change-Id: I65b801bb0b84c9d4983c3f4af6895a366ced0d7a
diff --git a/liblog/logger_name.c b/liblog/logger_name.c
index a5a83e0..979b82d 100644
--- a/liblog/logger_name.c
+++ b/liblog/logger_name.c
@@ -28,6 +28,7 @@
   [LOG_ID_EVENTS] = "events",
   [LOG_ID_SYSTEM] = "system",
   [LOG_ID_CRASH] = "crash",
+  [LOG_ID_STATS] = "stats",
   [LOG_ID_SECURITY] = "security",
   [LOG_ID_KERNEL] = "kernel",
   /* clang-format on */