Statsd namespace is defined and used

Statsd code now lives in android::os::statsd namespace. Existing files
are largely modified to follow this convention.

Exception: parse_util, since it seems a bit different.

Test: code compiles and existing statsd_tests still pass
Change-Id: Idf92a071b9ed172d01eb3087a4fa3609d67a038c
diff --git a/cmds/statsd/src/StatsLogProcessor.cpp b/cmds/statsd/src/StatsLogProcessor.cpp
index c2fffd8..1ae23ef 100644
--- a/cmds/statsd/src/StatsLogProcessor.cpp
+++ b/cmds/statsd/src/StatsLogProcessor.cpp
@@ -21,8 +21,10 @@
 #include <parse_util.h>
 
 using namespace android;
-using android::os::statsd::EventMetricData;
-using android::os::statsd::StatsLogReport;
+
+namespace android {
+namespace os {
+namespace statsd {
 
 StatsLogProcessor::StatsLogProcessor() : m_dropbox_writer("all-logs")
 {
@@ -71,3 +73,7 @@
     m_configs[config_source] = config;
     ALOGD("Updated configuration for source %i", config_source);
 }
+
+} // namespace statsd
+} // namespace os
+} // namespace android