Make StringPiece to be std::string_view alias

Bug: 237583012
Test: build + boot + UTs

Change-Id: I849831f4466d3b9c7ec842b75256e7fcba77a0c0
diff --git a/tools/aapt2/cmd/Diff.cpp b/tools/aapt2/cmd/Diff.cpp
index 423e939..5bfc732 100644
--- a/tools/aapt2/cmd/Diff.cpp
+++ b/tools/aapt2/cmd/Diff.cpp
@@ -78,7 +78,7 @@
   SymbolTable symbol_table_;
 };
 
-static void EmitDiffLine(const android::Source& source, const StringPiece& message) {
+static void EmitDiffLine(const android::Source& source, StringPiece message) {
   std::cerr << source << ": " << message << "\n";
 }