Adopt absl::string_view in modules/audio_coding/

Bug: webrtc:13579
Change-Id: Ifec66fb6ba9724d18539de7245a358c2d13c7939
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/268547
Reviewed-by: Ivo Creusen <ivoc@webrtc.org>
Reviewed-by: Tomas Gunnarsson <tommi@webrtc.org>
Commit-Queue: Ali Tofigh <alito@webrtc.org>
Cr-Commit-Position: refs/heads/main@{#37573}
diff --git a/modules/audio_coding/test/RTPFile.cc b/modules/audio_coding/test/RTPFile.cc
index 0c44e42..0c2ab3c 100644
--- a/modules/audio_coding/test/RTPFile.cc
+++ b/modules/audio_coding/test/RTPFile.cc
@@ -14,6 +14,8 @@
 
 #include <limits>
 
+#include "absl/strings/string_view.h"
+
 #ifdef WIN32
 #include <Winsock2.h>
 #else
@@ -122,9 +124,11 @@
   return _rtpQueue.empty();
 }
 
-void RTPFile::Open(const char* filename, const char* mode) {
-  if ((_rtpFile = fopen(filename, mode)) == NULL) {
-    printf("Cannot write file %s.\n", filename);
+void RTPFile::Open(absl::string_view filename, absl::string_view mode) {
+  std::string filename_str = std::string(filename);
+  if ((_rtpFile = fopen(filename_str.c_str(), std::string(mode).c_str())) ==
+      NULL) {
+    printf("Cannot write file %s.\n", filename_str.c_str());
     ADD_FAILURE() << "Unable to write file";
     exit(1);
   }