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/LogEntryPrinter.cpp b/cmds/statsd/src/LogEntryPrinter.cpp
index ba07308..c877b05 100644
--- a/cmds/statsd/src/LogEntryPrinter.cpp
+++ b/cmds/statsd/src/LogEntryPrinter.cpp
@@ -22,6 +22,10 @@
 
 using namespace android;
 
+namespace android {
+namespace os {
+namespace statsd {
+
 LogEntryPrinter::LogEntryPrinter(int out)
     :m_out(out)
 {
@@ -59,3 +63,7 @@
     }
 }
 
+} // namespace statsd
+} // namespace os
+} // namespace android
+