Modify mv rewrite rule on 'Count distinct'

[EmmyMiao87]

Proposed changes

The rewrite rule named CountToSum does not distinguish between Count and Count distinct which causes Count distinct is rewritten as Sum incorrectly.
So this commit modified matching rule.
When the function is Count distinct, the rewrite rule will not take effect.

Fixed #4381

Change-Id: I2b9fbde22c6bc91ba7310e630e29a7e96b909102

Types of changes

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• Bugfix (non-breaking change which fixes an issue)
• [] New feature (non-breaking change which adds functionality)
• [] Breaking change (fix or feature that would cause existing functionality to not work as expected)
• [] Documentation Update (if none of the other choices apply)
• [] Code refactor (Modify the code structure, format the code, etc...)

Checklist

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• I have create an issue on (Fix Query with Count distinct matches the incorrect materialized view  #4381), and have described the bug/feature there in detail
• Compiling and unit tests pass locally with my changes
• I have added tests that prove my fix is effective or that my feature works
• [] If this change need a document change, I have updated the document
• [] Any dependent changes have been merged

[morningman]

LGTM