message: Fix MetadataEncoderDecoderDeathTest.PackTooManyFrames in coverage build.
diff: @@ -333,6 +333,7 @@ using MetadataEncoderDecoderDeathTest = MetadataEncoderDecoderTest;
  // Crash if a caller tries to pack more frames than the encoder has data for.
  TEST_F(MetadataEncoderDecoderDeathTest, PackTooManyFrames) {
  + Logger::StderrSinkDelegate stderr_sink(Logger::Registry::getSink()); // For coverage build.
  MetadataMap metadata_map = {
  {"header_key1", std::string(5, 'a')},
  {"header_key2", std::string(5, 'b')},
  