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
diff --git a/core/res/AndroidManifest.xml b/core/res/AndroidManifest.xml
index 7af1b46..f257d5e 100644
--- a/core/res/AndroidManifest.xml
+++ b/core/res/AndroidManifest.xml
@@ -307,6 +307,8 @@
     <protected-broadcast android:name="android.intent.action.DREAMING_STOPPED" />
     <protected-broadcast android:name="android.intent.action.ANY_DATA_STATE" />
 
+    <protected-broadcast android:name="com.android.server.stats.action.TRIGGER_COLLECTION" />
+
     <protected-broadcast android:name="com.android.server.WifiManager.action.START_SCAN" />
     <protected-broadcast android:name="com.android.server.WifiManager.action.START_PNO" />
     <protected-broadcast android:name="com.android.server.WifiManager.action.DELAYED_DRIVER_STOP" />