Closes #18006: DefaultSessionControlControllerTest: Correctly unmock SearchStateKt class.

The test class left SearchStateKt mocked and caused other tests to fail intermittently when
running after it.

app/src/test/java/org/mozilla/fenix/home/DefaultSessionControlControllerTest.kt

@@ -468,7 +468,7 @@ class DefaultSessionControlControllerTest {
                 )
             }
         } finally {
-            unmockkStatic(SearchState::class)
+            unmockkStatic("mozilla.components.browser.state.state.SearchStateKt")
         }
     }