Fix fallback issue when executing 'select count(*)' or 'select count(1)'

**Describe the bug**
When executing 'select count(*)' or 'select count(1)', ProjectExec will fallback.

**To Reproduce**
Steps to reproduce the behavior:

**Expected behavior**
A clear and concise description of what you expected to happen.

**Additional context**
Add any other context about the problem here.
