Update MockWebServer MockResponse test for nested-type render change

[steve-aom-elliott]

The UpdateMockWebServerMockResponseTest.shouldMigrateMockResponseToBuilder() test started failing against the latest rewrite snapshot (8.85.0-SNAPSHOT).

Root cause

• openrewrite/rewrite#7993 changed ChangeMethodInvocationReturnType to rewrite a variable’s declared type only when the variable’s initializer is the matched invocation, not when the match is merely nested inside the initializer.

In this test, mockResponse’s initializer is a chain whose outermost call is setHeader(...), which is not in the recipe’s replacement map — so the matched setStatus(...) is nested, not the initializer. The declared-type change is therefore now performed by the later ChangeType step (rather than ChangeMethodInvocationReturnType), and ChangeType renders the nested type in qualified MockResponse.Builder form (reusing the existing mockwebserver3.MockResponse import) instead of importing mockwebserver3.MockResponse.Builder and using the simple name Builder.

Change

Update the expected output of shouldMigrateMockResponseToBuilder:

 import mockwebserver3.MockResponse;
-import mockwebserver3.MockResponse.Builder;
 ...
-    private Builder mockResponse = new MockResponse.Builder()
+    private MockResponse.Builder mockResponse = new MockResponse.Builder()

This matches the new (more correct, consistent) output — mockResponse2 in the same test already renders as MockResponse.Builder.

Verification

• Pinned core org.openrewrite modules to 8.84.7 (pre-#7993): test passes.
• Against 8.85.0-SNAPSHOT (has #7993): test fails before this change, passes after.