Replace StringPiece with std::string_view in art/runtime/.

And in art/test/.

Test: m test-art-host-gtest
Test: testrunner.py --host --optimizing
Bug: 123750182
Change-Id: I14c7cddd7ba4fb2183c643d32a89b594008d8bd0
diff --git a/runtime/runtime.cc b/runtime/runtime.cc
index feade83..97dccb0 100644
--- a/runtime/runtime.cc
+++ b/runtime/runtime.cc
@@ -1173,8 +1173,8 @@
 
   compiler_executable_ = runtime_options.ReleaseOrDefault(Opt::Compiler);
   compiler_options_ = runtime_options.ReleaseOrDefault(Opt::CompilerOptions);
-  for (StringPiece option : Runtime::Current()->GetCompilerOptions()) {
-    if (option.starts_with("--debuggable")) {
+  for (const std::string& option : Runtime::Current()->GetCompilerOptions()) {
+    if (option == "--debuggable") {
       SetJavaDebuggable(true);
       break;
     }