Declare 2 VideoEncoder::EncoderInfo vars as const

Declare two VideoEncoder::EncoderInfo local variables as const. This
makes it clear that they are equal to the return value of
encoder_->GetEncoderInfo().

Bug: None
Change-Id: I08ab34e670e6eb1cb3c67a48b4e9826902d9d9fa
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/293385
Reviewed-by: Erik Språng <sprang@webrtc.org>
Commit-Queue: Wan-Teh Chang <wtc@google.com>
Cr-Commit-Position: refs/heads/main@{#39321}

video/video_stream_encoder.cc

diff --git a/video/video_stream_encoder.cc b/video/video_stream_encoder.cc
index af808c1..176b3a1 100644
--- a/video/video_stream_encoder.cc
+++ b/video/video_stream_encoder.cc
@@ -1341,7 +1341,7 @@
       field_trials_.IsDisabled(kFrameDropperFieldTrial) ||
       (num_layers > 1 && codec.mode == VideoCodecMode::kScreensharing);
 
-  VideoEncoder::EncoderInfo info = encoder_->GetEncoderInfo();
+  const VideoEncoder::EncoderInfo info = encoder_->GetEncoderInfo();
   if (rate_control_settings_.UseEncoderBitrateAdjuster()) {
     bitrate_adjuster_ = std::make_unique<EncoderBitrateAdjuster>(codec);
     bitrate_adjuster_->OnEncoderInfo(info);
@@ -1869,7 +1869,7 @@
   TraceFrameDropEnd();
 
   // Encoder metadata needs to be updated before encode complete callback.
-  VideoEncoder::EncoderInfo info = encoder_->GetEncoderInfo();
+  const VideoEncoder::EncoderInfo info = encoder_->GetEncoderInfo();
   if (info.implementation_name != encoder_info_.implementation_name ||
       info.is_hardware_accelerated != encoder_info_.is_hardware_accelerated) {
     encoder_stats_observer_->OnEncoderImplementationChanged({