What/Where is the issue ?

When collecting KPI results in the context of digest creation, if there is a report with a null value, the digest fails with an NPE

Environment: C7/ C8SaaS/ C8SM

Optimize version : 3.9.5+, 3.10.3+
ES version : All
OS + Browser version : All

Steps to reproduce:

• Preconditions: Have a KPI report with null value (duration report, not count report)
• Steps: Create a digest, observe the logs

Observed behavior:

The digest email NPEs and can't be created

Expected behavior:

The digest email can be created and contains the report, even if the value is null

Additional Information:

Backport to 3.9 and 3.10 maintenance branches