Bug 1878434 - Record an awesomebar abandonment for cancelled toolbar edits.

We were missing instrumentation for the case where the user cancels
editing. This commit adds that instrumentation.

app/src/main/java/org/mozilla/fenix/search/SearchDialogController.kt

@@ -143,6 +143,7 @@ class SearchDialogController(
     override fun handleEditingCancelled() {
         clearToolbarFocus()
         dismissDialogAndGoBack()
+        store.dispatch(AwesomeBarAction.EngagementFinished(abandoned = true))
     }
 
     override fun handleTextChanged(text: String) {

app/src/test/java/org/mozilla/fenix/search/SearchDialogControllerTest.kt

@@ -313,6 +313,10 @@ class SearchDialogControllerTest {
 
         assertTrue(clearToolbarFocusInvoked)
         assertTrue(dismissAndGoBack)
+
+        middleware.assertLastAction(AwesomeBarAction.EngagementFinished::class) { action ->
+            assertTrue(action.abandoned)
+        }
     }
 
     @Test