Move ActionParser to its own file

Bug: 36970783
Test: build
Change-Id: Idd5b923e4789760bb9ef67c10982b2642bc6a31a
diff --git a/init/init_test.cpp b/init/init_test.cpp
index 268873c..d78aabd 100644
--- a/init/init_test.cpp
+++ b/init/init_test.cpp
@@ -21,6 +21,7 @@
 #include <gtest/gtest.h>
 
 #include "action.h"
+#include "action_parser.h"
 #include "builtins.h"
 #include "import_parser.h"
 #include "keyword_map.h"