Concatenate string literals at compile time.

This CL was generated by running:
git ls-files | grep ".cc" | xargs perl -i -ne 'BEGIN {undef $/}; s/("[\s\n]*<<[\s\n]*")/" "/g; print;'; git cl format

After that I manually edited modules/audio_processing/gain_controller2.cc to preserve its original
formatting.

This primary benefit of this change is a small reduction in binary size.

Bug: None
Change-Id: I689fa7ba9c717c314bb167e5d592c3c4e0871e29
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/165961
Reviewed-by: Alessio Bazzica <alessiob@webrtc.org>
Reviewed-by: Karl Wiberg <kwiberg@webrtc.org>
Commit-Queue: Jonas Olsson <jonasolsson@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#30251}

modules/video_coding/packet_buffer.cc

@@ -357,8 +357,8 @@ std::vector<std::unique_ptr<RtpFrameObject>> PacketBuffer::FindFrames(
         if (has_h264_idr && (!has_h264_sps || !has_h264_pps)) {
           RTC_LOG(LS_WARNING)
               << "Received H.264-IDR frame "
-              << "(SPS: " << has_h264_sps << ", PPS: " << has_h264_pps
-              << "). Treating as "
+                 "(SPS: "
+              << has_h264_sps << ", PPS: " << has_h264_pps << "). Treating as "
               << (sps_pps_idr_is_h264_keyframe_ ? "delta" : "key")
               << " frame since WebRTC-SpsPpsIdrIsH264Keyframe is "
               << (sps_pps_idr_is_h264_keyframe_ ? "enabled." : "disabled");