Fix clang-tidy performance warnings in aapt2.

* Use const reference parameter type to avoid unnecessary copy.
* Use more efficient overloaded string methods.

Bug: 30407689
Bug: 30411878
Test: build with WITH_TIDY=1
Change-Id: Iaa0a6f18f64cf573bee49dd1466281ea4d37b410
diff --git a/tools/aapt2/cmd/Link.cpp b/tools/aapt2/cmd/Link.cpp
index e6bf3a6..3e3f432 100644
--- a/tools/aapt2/cmd/Link.cpp
+++ b/tools/aapt2/cmd/Link.cpp
@@ -915,7 +915,7 @@
 
   bool WriteJavaFile(ResourceTable* table, const StringPiece& package_name_to_generate,
                      const StringPiece& out_package, const JavaClassGeneratorOptions& java_options,
-                     const Maybe<std::string> out_text_symbols_path = {}) {
+                     const Maybe<std::string>& out_text_symbols_path = {}) {
     if (!options_.generate_java_class_path) {
       return true;
     }