Fix a race condition in TextFieldTextToolbarTest

Run `focusRequester.requestFocus()` from main thread to avoid a possible race condition.

Test: TextFieldTextToolbarTest
Fix: 414646157
Change-Id: Icd1de9a5ca300391b30f32861391b4cc79c68db5
diff --git a/compose/foundation/foundation/src/androidInstrumentedTest/kotlin/androidx/compose/foundation/text/input/internal/selection/TextFieldTextToolbarTest.kt b/compose/foundation/foundation/src/androidInstrumentedTest/kotlin/androidx/compose/foundation/text/input/internal/selection/TextFieldTextToolbarTest.kt
index cdf4a25..4d1f3f6 100644
--- a/compose/foundation/foundation/src/androidInstrumentedTest/kotlin/androidx/compose/foundation/text/input/internal/selection/TextFieldTextToolbarTest.kt
+++ b/compose/foundation/foundation/src/androidInstrumentedTest/kotlin/androidx/compose/foundation/text/input/internal/selection/TextFieldTextToolbarTest.kt
@@ -850,7 +850,7 @@
 
         rule.runOnIdle { assertThat(textToolbar.status).isEqualTo(TextToolbarStatus.Shown) }
 
-        focusRequester.requestFocus()
+        rule.runOnUiThread { focusRequester.requestFocus() }
 
         rule.runOnIdle { assertThat(textToolbar.status).isEqualTo(TextToolbarStatus.Hidden) }
     }