telemetry(amazonq): add optional field to validateProject metric for SQL conversions (aws#909)

## Problem

Want to be able to track various metadata, such as how often a project
is eligible for both language upgrade and SQL conversion.

## Solution

Add an optional field to an existing metric.

<!---
    REMINDER:
    - Read CONTRIBUTING.md first.
    - Add test coverage for your changes.
    - Link to related issues/commits.
    - Testing: how did you test your changes?
    - Screenshots if applicable
-->

## License

By submitting this pull request, I confirm that my contribution is made
under the terms of the Apache 2.0 license.

---------

Co-authored-by: David Hasani <[email protected]>

Author: dhasani23

telemetry/definitions/commonDefinitions.json

@@ -470,6 +470,11 @@
             "type": "string",
             "description": "A unique upload ID for S3"
         },
+        {
+            "name": "codeTransformValidationMetadata",
+            "type": "string",
+            "description": "A field for storing various validation metadata"
+        },
         {
             "name": "codeTransformVCSViewerSrcComponents",
             "type": "string",
@@ -4181,6 +4186,10 @@
                     "type": "codeTransformSessionId",
                     "required": true
                 },
+                {
+                    "type": "codeTransformValidationMetadata",
+                    "required": false
+                },
                 {
                     "type": "reason",
                     "required": false