Read .rc files from bootstrap apexes

To start an early_hal service from a bootstrap vendor apex, init now
reads .rc files from bootstrap apexes as well.

In this change, perform_apex_config command is re-purposed to support
bootstrap mode. Now we have some similarity between two apexd calls:

- for bootstrap apexes (in the bootstrap mount namespace):

  exec_start apexd-bootstrap
  perform_apex_config --bootstrap

- for normal apexes (in the default mount namespace):

  restart apexd
  ...
  wait_for_prop apexd.status activated
  perform_apex_config

Note that some tasks in perform_apex_config are not needed in the
bootstrap.  For example, we don't need to create apexdata directories
for bootstrap apexes.

Bug: 290148081
Test: VendorApexHostTestCases
Change-Id: I8f683a4dcd7cd9a2466a4b1b417d84c025c37761
diff --git a/init/builtins.cpp b/init/builtins.cpp
index fa5e36d..e40b831 100644
--- a/init/builtins.cpp
+++ b/init/builtins.cpp
@@ -1292,10 +1292,21 @@
 }
 
 static Result<void> do_perform_apex_config(const BuiltinArguments& args) {
-    auto create_dirs = create_apex_data_dirs();
-    if (!create_dirs.ok()) {
-        return create_dirs.error();
+    bool bootstrap = false;
+    if (args.size() == 2) {
+        if (args[1] != "--bootstrap") {
+            return Error() << "Unexpected argument: " << args[1];
+        }
+        bootstrap = true;
     }
+
+    if (!bootstrap) {
+        auto create_dirs = create_apex_data_dirs();
+        if (!create_dirs.ok()) {
+            return create_dirs.error();
+        }
+    }
+
     auto parse_configs = ParseApexConfigs(/*apex_name=*/"");
     if (!parse_configs.ok()) {
         return parse_configs.error();
@@ -1306,8 +1317,10 @@
         return update_linker_config.error();
     }
 
-    // Now start delayed services
-    ServiceList::GetInstance().MarkServicesUpdate();
+    if (!bootstrap) {
+        // Now start delayed services
+        ServiceList::GetInstance().MarkServicesUpdate();
+    }
     return {};
 }
 
@@ -1362,7 +1375,7 @@
         // mount and umount are run in the same context as mount_all for symmetry.
         {"mount_all",               {0,     kMax, {false,  do_mount_all}}},
         {"mount",                   {3,     kMax, {false,  do_mount}}},
-        {"perform_apex_config",     {0,     0,    {false,  do_perform_apex_config}}},
+        {"perform_apex_config",     {0,     1,    {false,  do_perform_apex_config}}},
         {"umount",                  {1,     1,    {false,  do_umount}}},
         {"umount_all",              {0,     1,    {false,  do_umount_all}}},
         {"update_linker_config",    {0,     0,    {false,  do_update_linker_config}}},