aapt2: avoid vector<const T>

A container of const T uses std::allocator<const T>, which was an
undocumented libc++ extension that has been removed.

See https://github.com/llvm/llvm-project/pull/96319.

Bug: 349681543
Test: m libaapt2
Change-Id: Ic712f8c844b05687948162e5d080af3726b322f6
diff --git a/tools/aapt2/util/Files.cpp b/tools/aapt2/util/Files.cpp
index 02e4beae..8ae55b8 100644
--- a/tools/aapt2/util/Files.cpp
+++ b/tools/aapt2/util/Files.cpp
@@ -189,7 +189,7 @@
   base->append(part.data(), part.size());
 }
 
-std::string BuildPath(std::vector<const StringPiece>&& args) {
+std::string BuildPath(const std::vector<StringPiece>& args) {
   if (args.empty()) {
     return "";
   }