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/descriptors.h b/init/descriptors.h
index ff276fb..3bdddfe 100644
--- a/init/descriptors.h
+++ b/init/descriptors.h
@@ -22,6 +22,9 @@
 
 #include <string>
 
+namespace android {
+namespace init {
+
 class DescriptorInfo {
  public:
   DescriptorInfo(const std::string& name, const std::string& type, uid_t uid,
@@ -75,4 +78,7 @@
   virtual const std::string key() const override;
 };
 
+}  // namespace init
+}  // namespace android
+
 #endif