test(amazonq): update view diff test (aws#6777)

## Problem
- source code change for /test which adds a test plan summary after
generating tests, but did not update e2e test to account for this

## Solution
- update test

---

- Treat all work as PUBLIC. Private `feature/x` branches will not be
squash-merged at release time.
- Your code changes must meet the guidelines in
[CONTRIBUTING.md](https://github.com/aws/aws-toolkit-vscode/blob/master/CONTRIBUTING.md#guidelines).
- License: I confirm that my contribution is made under the terms of the
Apache 2.0 license.

Author: chungjac

packages/amazonq/test/e2e/amazonq/testGen.test.ts

@@ -194,9 +194,12 @@ describe('Amazon Q Test Generation', function () {
                         const viewDiffMessage = chatItems[5]
 
                         assert.deepStrictEqual(viewDiffMessage.type, 'answer')
-                        assert.deepStrictEqual(
-                            viewDiffMessage.body,
+                        const expectedEnding =
                             'Please see the unit tests generated below. Click “View diff” to review the changes in the code editor.'
+                        assert.strictEqual(
+                            viewDiffMessage.body?.includes(expectedEnding),
+                            true,
+                            `View diff message does not contain phrase: ${expectedEnding}`
                         )
                     })
                 })