updater: Add a testcase for RenameFn().

Test: recovery_component_test passes.

Change-Id: Iba5a0fdf6c79e2bed6b30b8fc19a306c1ab29d8a
diff --git a/updater/install.cpp b/updater/install.cpp
index 25f6a91..ed55ea5 100644
--- a/updater/install.cpp
+++ b/updater/install.cpp
@@ -293,7 +293,7 @@
     }
 
     int64_t size;
-    if (!android::base::ParseInt(fs_size.c_str(), &size)) {
+    if (!android::base::ParseInt(fs_size, &size)) {
         return ErrorAbort(state, kArgsParsingFailure,
                           "%s: failed to parse int in %s\n", name, fs_size.c_str());
     }
@@ -329,6 +329,9 @@
     return nullptr;
 }
 
+// rename(src_name, dst_name)
+//   Renames src_name to dst_name. It automatically creates the necessary directories for dst_name.
+//   Example: rename("system/app/Hangouts/Hangouts.apk", "system/priv-app/Hangouts/Hangouts.apk")
 Value* RenameFn(const char* name, State* state, int argc, Expr* argv[]) {
     if (argc != 2) {
         return ErrorAbort(state, kArgsParsingFailure, "%s() expects 2 args, got %d", name, argc);