Make StringPiece to be std::string_view alias

Bug: 237583012
Test: build + boot + UTs

Change-Id: I849831f4466d3b9c7ec842b75256e7fcba77a0c0
diff --git a/tools/aapt2/text/Unicode.cpp b/tools/aapt2/text/Unicode.cpp
index 3735b3e..5e25be3 100644
--- a/tools/aapt2/text/Unicode.cpp
+++ b/tools/aapt2/text/Unicode.cpp
@@ -77,7 +77,7 @@
          (codepoint == 0x3000);
 }
 
-bool IsJavaIdentifier(const StringPiece& str) {
+bool IsJavaIdentifier(StringPiece str) {
   Utf8Iterator iter(str);
 
   // Check the first character.
@@ -99,7 +99,7 @@
   return true;
 }
 
-bool IsValidResourceEntryName(const StringPiece& str) {
+bool IsValidResourceEntryName(StringPiece str) {
   Utf8Iterator iter(str);
 
   // Check the first character.