Split init's source files init first stage and second stage

This is a baseline for splitting init first and second stage into
their own executables.

Bug: 79758715
Test: sailfish boots
Change-Id: I549ad4502893b3a5e4c2a9886f66850f6d31b619
diff --git a/init/Android.bp b/init/Android.bp
index a93bb66..d42ab8a 100644
--- a/init/Android.bp
+++ b/init/Android.bp
@@ -107,6 +107,7 @@
         "first_stage_mount.cpp",
         "import_parser.cpp",
         "init.cpp",
+        "init_first_stage.cpp",
         "keychords.cpp",
         "modalias_handler.cpp",
         "parser.cpp",
@@ -115,6 +116,7 @@
         "property_service.cpp",
         "property_type.cpp",
         "reboot.cpp",
+        "reboot_utils.cpp",
         "security.cpp",
         "selinux.cpp",
         "service.cpp",