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/audio_processing/test/py_quality_assessment/quality_assessment/sound_level.cc

@@ -76,9 +76,14 @@ int main(int argc, char* argv[]) {
   // Write config to file.
   std::ofstream out_config(config_output_file);
   out_config << "{"
-             << "'frame_len_ms': " << absl::GetFlag(FLAGS_f) << ", "
-             << "'attack_ms': " << absl::GetFlag(FLAGS_a) << ", "
-             << "'decay_ms': " << absl::GetFlag(FLAGS_d) << "}\n";
+                "'frame_len_ms': "
+             << absl::GetFlag(FLAGS_f)
+             << ", "
+                "'attack_ms': "
+             << absl::GetFlag(FLAGS_a)
+             << ", "
+                "'decay_ms': "
+             << absl::GetFlag(FLAGS_d) << "}\n";
   out_config.close();
 
   // Measure level frame-by-frame.