Copy webapp's YAML file to the coverage output directory (#24545)

diff --git a/scripts/build_coverage.sh b/scripts/build_coverage.sh
index c8aa555..f88129a 100755
--- a/scripts/build_coverage.sh
+++ b/scripts/build_coverage.sh
@@ -168,3 +168,6 @@
 lcov --capture --directory "$OUTPUT_ROOT/obj/src" --exclude="$PWD"/zzz_generated/* --exclude="$PWD"/third_party/* --exclude=/usr/include/* --output-file "$COVERAGE_ROOT/lcov_test.info"
 lcov --add-tracefile "$COVERAGE_ROOT/lcov_base.info" --add-tracefile "$COVERAGE_ROOT/lcov_test.info" --output-file "$COVERAGE_ROOT/lcov_final.info"
 genhtml "$COVERAGE_ROOT/lcov_final.info" --output-directory "$COVERAGE_ROOT/html"
+
+# Copy webapp's YAML file to the coverage output directory
+cp "$CHIP_ROOT/integrations/appengine/webapp_config.yaml" "$COVERAGE_ROOT/webapp_config.yaml"