Adds client API for interacting with statsd.

This API will primarily be used by GmsCore to send updated configs.
Also, sending a config will implicitly notify the StatsD that this
client wants to know when it should request data for this config.

We send a broadcast so that all interested subscribers can know if
data needs to be pulled.

Test: Manually tested that sending broadcast works via new adb
command added in StatsService.

Change-Id: I23cdd1df706036e14b32c3d01af30c3d4af819fa

bin/src/config/ConfigManager.cpp

diff --git a/bin/src/config/ConfigManager.cpp b/bin/src/config/ConfigManager.cpp
index d86ab57..2a8a741 100644
--- a/bin/src/config/ConfigManager.cpp
+++ b/bin/src/config/ConfigManager.cpp
@@ -60,6 +60,14 @@
     }
 }
 
+void ConfigManager::SetConfigReceiver(const ConfigKey& key, const string& pkg, const string& cls) {
+    mConfigReceivers[key] = pair<string, string>(pkg, cls);
+}
+
+void ConfigManager::RemoveConfigReceiver(const ConfigKey& key) {
+    mConfigReceivers.erase(key);
+}
+
 void ConfigManager::RemoveConfig(const ConfigKey& key) {
     unordered_map<ConfigKey, StatsdConfig>::iterator it = mConfigs.find(key);
     if (it != mConfigs.end()) {
@@ -85,6 +93,7 @@
         if (it->first.GetUid() == uid) {
             removed.push_back(it->first);
             it = mConfigs.erase(it);
+            mConfigReceivers.erase(it->first);
         } else {
             it++;
         }