Add bash logging for create_pr.sh (#3110)

* add bash logging for create_pr.sh

* add start and finish lines to make the script clear in logs

Author: rcrozean

build/update-attribution-files/create_pr.sh

@@ -14,8 +14,11 @@
 # limitations under the License.
 
 set -e
+set -x
 set -o pipefail
 
+echo "===== Starting ${BASH_SOURCE[0]} ====="
+
 if [[ -z "$JOB_TYPE" ]]; then
     exit 0
 fi
@@ -242,3 +245,5 @@ for FILE in $(find . -type f \( -name go.sum -o -name go.mod \)); do
 done
 
 pr::create::go-mod
+
+echo "===== Ending ${BASH_SOURCE[0]} ====="