Use IMM.hideSoftInputFromWindow to close the window

Bug: 187589678
Test: manual
Change-Id: Id46a36432a03638877f854f32bfa03183c7cb019
diff --git a/src/com/android/launcher3/util/UiThreadHelper.java b/src/com/android/launcher3/util/UiThreadHelper.java
index 523f3d6..947f96f 100644
--- a/src/com/android/launcher3/util/UiThreadHelper.java
+++ b/src/com/android/launcher3/util/UiThreadHelper.java
@@ -50,11 +50,9 @@
             WindowInsets rootInsets = root.getRootWindowInsets();
             boolean isImeShown = rootInsets != null && rootInsets.isVisible(
                     WindowInsets.Type.ime());
-            if (isImeShown) {
-                // this call is already asynchronous
-                root.getWindowInsetsController().hide(WindowInsets.Type.ime());
+            if (!isImeShown) {
+                return;
             }
-            return;
         }
 
         Message.obtain(HANDLER.get(root.getContext()),