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/init.cpp b/init/init.cpp
index d6e9130..0562dad 100644
--- a/init/init.cpp
+++ b/init/init.cpp
@@ -48,7 +48,6 @@
 #include <libavb/libavb.h>
 #include <private/android_filesystem_config.h>
 #include <selinux/android.h>
-#include <selinux/label.h>
 #include <selinux/selinux.h>
 
 #include <fstream>
@@ -75,6 +74,9 @@
 using android::base::boot_clock;
 using android::base::GetProperty;
 
+namespace android {
+namespace init {
+
 struct selabel_handle *sehandle;
 struct selabel_handle *sehandle_prop;
 
@@ -1156,3 +1158,10 @@
 
     return 0;
 }
+
+}  // namespace init
+}  // namespace android
+
+int main(int argc, char** argv) {
+    android::init::main(argc, argv);
+}