Add log source filtering in statsd to filter out spams.

+ Add log source whitelist in StatsdConfig
+ Some changes in UidMap API. Listener needs to be wp instead of sp.
+ Update dogfood app config to have log source
+ Increase the stats service thread pool size to 10 (9+1).

TODO: add unit tests(b/70805664). This unit test takes some time to write.

Test: statsd_test & manual

Change-Id: I129b1cc13db5114db7417580962bd7cc4438519d
diff --git a/cmds/statsd/src/main.cpp b/cmds/statsd/src/main.cpp
index 41b24bc..4ce4768 100644
--- a/cmds/statsd/src/main.cpp
+++ b/cmds/statsd/src/main.cpp
@@ -105,7 +105,7 @@
 
     // Set up the binder
     sp<ProcessState> ps(ProcessState::self());
-    ps->setThreadPoolMaxThreadCount(1);  // everything is oneway, let it queue and save ram
+    ps->setThreadPoolMaxThreadCount(9);
     ps->startThreadPool();
     ps->giveThreadPoolName();
     IPCThreadState::self()->disableBackgroundScheduling(true);