Prevent errors due to non-existing console.html

Grep and stat were producing the error "No such file or directory"
while the consoleLog was not available to download. Keeping an empty
/tmp/console.html resolves the problem. It's also possible to debug any
possible issues with curl and grep independently since curl would
report 404 for missing url and a new error message was introduced
for missing UUID after the max retries.

Change-Id: Icb28bfca96e5eaff725d2efcfb47c3399e3991c4

jenkins/scripts/grab_console_log.sh

@@ -7,8 +7,8 @@ END_UUID=$(cat /proc/sys/kernel/random/uuid)
 
 echo "Grabbing consoleLog ($END_UUID)"
 
-# Since we are appending to fetched logs, remove any possibly old runs
-rm -f /tmp/console.html
+# Since we are appending to fetched logs, clear any possibly old runs
+echo > /tmp/console.html
 
 # Grab the HTML version of the log (includes timestamps)
 TRIES=0
@@ -16,6 +16,7 @@ console_log_path='logText/progressiveHtml'
 while ! grep -q "$END_UUID" /tmp/console.html; do
     TRIES=$((TRIES+1))
     if [ $TRIES -gt $RETRY_LIMIT ]; then
+        echo "Failed grabbing consoleLog within $RETRY_LIMIT retries."
         break
     fi
     sleep 3