Create blank coverage reports before running tests

This ensures that the output file bazel expects exists even if the
coverage test task times out.  If it does not exist then the final
coverage-aggregation action will not run because it is missing an
input file.

Closes #13278.

PiperOrigin-RevId: 366964262

tools/test/collect_coverage.sh

diff --git a/tools/test/collect_coverage.sh b/tools/test/collect_coverage.sh
index 43efda7..4a1b82c 100755
--- a/tools/test/collect_coverage.sh
+++ b/tools/test/collect_coverage.sh
@@ -146,15 +146,15 @@
   # TODO(bazel-team): cd should be avoided.
   cd "$TEST_SRCDIR/$TEST_WORKSPACE"
 
-  # Execute the test.
-  "$@"
-  TEST_STATUS=$?
-
   # Always create the coverage report.
   if [[ "$SPLIT_COVERAGE_POST_PROCESSING" == "0" ]]; then
     touch $COVERAGE_OUTPUT_FILE
   fi
 
+  # Execute the test.
+  "$@"
+  TEST_STATUS=$?
+
   if [[ $TEST_STATUS -ne 0 ]]; then
     echo --
     echo Coverage runner: Not collecting coverage for failed test.