Fix stack-use-after-scope for a `std::string`

`android::util::Utf16ToUtf8()` actually returns a `std::string` due to
the actual conversion to Utf8. `ParseResourceNamedType()` operates on a
`StringPiece` of `converted` (the `std::string` returned from that
call), and stashes it away for later use. Of course, by the time we're
using the `StringPiece` in `parsed_type`, `converted` has already gone
out of scope and is invalid to access.

Bug: http://b/250827883
Test: ./art/test/testrunner/run_build_test_target.py -j80 art-asan

Change-Id: Iea71a5cc84b7dfa96e7dcb549435f8394770a4df
diff --git a/tools/aapt2/ResourceUtils.cpp b/tools/aapt2/ResourceUtils.cpp
index 945f45b..41c7435 100644
--- a/tools/aapt2/ResourceUtils.cpp
+++ b/tools/aapt2/ResourceUtils.cpp
@@ -43,8 +43,9 @@
 static std::optional<ResourceNamedType> ToResourceNamedType(const char16_t* type16,
                                                             const char* type, size_t type_len) {
   std::optional<ResourceNamedTypeRef> parsed_type;
+  std::string converted;
   if (type16) {
-    auto converted = android::util::Utf16ToUtf8(StringPiece16(type16, type_len));
+    converted = android::util::Utf16ToUtf8(StringPiece16(type16, type_len));
     parsed_type = ParseResourceNamedType(converted);
   } else if (type) {
     parsed_type = ParseResourceNamedType(StringPiece(type, type_len));