Copying debug ramdisk files to /debug_ramdisk/*

In previous implementation, userdebug sepoilcy and property files are
loaded from the system.img. This CL changes this to:

  - first-stage init copies userdebug files from ramdisk to /debug_ramisk/*
  - second-stage init loads files from /debug_ramdisk/*.

Note: same as before, the above can only be triggered, if the device
is UNLOCKED

With this, we don't have to put userdebug related files into the USER
system.img.

Bug: 126493225
Test: boot device with a ramdisk with /force_debuggable, checks related
      files are loaded
Change-Id: I63f5f846e82ba78427062bf7615c26173878d8f3
diff --git a/init/selinux.cpp b/init/selinux.cpp
index aa66baa..132fc13 100644
--- a/init/selinux.cpp
+++ b/init/selinux.cpp
@@ -64,6 +64,7 @@
 #include <fs_avb/fs_avb.h>
 #include <selinux/android.h>
 
+#include "debug_ramdisk.h"
 #include "reboot_utils.h"
 #include "util.h"
 
@@ -271,8 +272,6 @@
 }
 
 constexpr const char plat_policy_cil_file[] = "/system/etc/selinux/plat_sepolicy.cil";
-constexpr const char userdebug_plat_policy_cil_file[] =
-        "/system/etc/selinux/userdebug_plat_sepolicy.cil";
 
 bool IsSplitPolicyDevice() {
     return access(plat_policy_cil_file, R_OK) != -1;
@@ -292,7 +291,7 @@
     const char* force_debuggable_env = getenv("INIT_FORCE_DEBUGGABLE");
     bool use_userdebug_policy =
             ((force_debuggable_env && "true"s == force_debuggable_env) &&
-             AvbHandle::IsDeviceUnlocked() && access(userdebug_plat_policy_cil_file, F_OK) == 0);
+             AvbHandle::IsDeviceUnlocked() && access(kDebugRamdiskSEPolicy, F_OK) == 0);
     if (use_userdebug_policy) {
         LOG(WARNING) << "Using userdebug system sepolicy";
     }
@@ -367,7 +366,7 @@
     // clang-format off
     std::vector<const char*> compile_args {
         "/system/bin/secilc",
-        use_userdebug_policy ? userdebug_plat_policy_cil_file : plat_policy_cil_file,
+        use_userdebug_policy ? kDebugRamdiskSEPolicy: plat_policy_cil_file,
         "-m", "-M", "true", "-G", "-N",
         "-c", version_as_string.c_str(),
         plat_mapping_file.c_str(),