Avoid more usage of implicit conversion from scoped_refptr<T> to T*

Update api/, call/, examples/ and rtc_tools/.

Bug: webrtc:13464
Change-Id: I7b0008cca68c579e89b45527a45300d1e67c3483
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/260000
Reviewed-by: Henrik Boström <hbos@webrtc.org>
Reviewed-by: Magnus Jedvert <magjed@webrtc.org>
Commit-Queue: Niels Moller <nisse@webrtc.org>
Cr-Commit-Position: refs/heads/main@{#36673}
diff --git a/api/video_codecs/video_encoder_config.cc b/api/video_codecs/video_encoder_config.cc
index 206a1d3..92568d7 100644
--- a/api/video_codecs/video_encoder_config.cc
+++ b/api/video_codecs/video_encoder_config.cc
@@ -79,7 +79,7 @@
       break;
   }
   ss << ", encoder_specific_settings: ";
-  ss << (encoder_specific_settings != NULL ? "(ptr)" : "NULL");
+  ss << (encoder_specific_settings != nullptr ? "(ptr)" : "NULL");
 
   ss << ", min_transmit_bitrate_bps: " << min_transmit_bitrate_bps;
   ss << '}';