Convert quiche_lower_case_string_impl.h over to the new-style #include path.

PiperOrigin-RevId: 439693303

common/platform/api/quiche_lower_case_string.h

diff --git a/common/platform/api/quiche_lower_case_string.h b/common/platform/api/quiche_lower_case_string.h
index 4492b3c..dcaef3c 100644
--- a/common/platform/api/quiche_lower_case_string.h
+++ b/common/platform/api/quiche_lower_case_string.h
@@ -5,7 +5,7 @@
 #ifndef QUICHE_COMMON_PLATFORM_API_QUICHE_LOWER_CASE_STRING_H_
 #define QUICHE_COMMON_PLATFORM_API_QUICHE_LOWER_CASE_STRING_H_
 
-#include "net/quiche/common/platform/impl/quiche_lower_case_string_impl.h"
+#include "quiche_platform_impl/quiche_lower_case_string_impl.h"
 
 namespace quiche {