init: create android::init:: namespace

With some small fixups along the way

Test: Boot bullhead
Test: init unit tests
Change-Id: I7beaa473cfa9397f845f810557d1631b4a462d6a
diff --git a/init/bootchart.cpp b/init/bootchart.cpp
index 825603a..4727f92 100644
--- a/init/bootchart.cpp
+++ b/init/bootchart.cpp
@@ -40,6 +40,9 @@
 using android::base::StringPrintf;
 using namespace std::chrono_literals;
 
+namespace android {
+namespace init {
+
 static std::thread* g_bootcharting_thread;
 
 static std::mutex g_bootcharting_finished_mutex;
@@ -192,3 +195,6 @@
   if (args[1] == "start") return do_bootchart_start();
   return do_bootchart_stop();
 }
+
+}  // namespace init
+}  // namespace android