Update the example of attributes processor to be consistent with the comment (#3334)

Update attributes in the `config.yaml` of attributes processor. So the regex value is consistent with the comment above it, as suggested in the issue.

**Link to tracking Issue:**
#2843

Author: Saber-W

processor/attributesprocessor/testdata/config.yaml

@@ -294,7 +294,7 @@ processors:
       match_type: regexp
       attributes:
         # This attribute ('db.statement') must exist in the span and match the regex ('SELECT \* FROM USERS.*') for a match.
-        - {key: env, value: "'SELECT * FROM USERS WHERE ID=1'"}
+        - {key: env, value: 'SELECT \* FROM USERS.*'}
     actions:
       - key: db.statement
         action: update