Apply new flow to hint user about triple-tap will delay when user select triple-tap shortcut on window-mode.

Root Cause: Original content in magnification switch shortcut dialog needs to have different versions for different accessibility software shortcuts. Use the generic content and new flow to replace it.

Solution: Apply new flow from UX suggestion.

Bug: 210593079
Test: make RunSettingsRoboTests ROBOTEST_FILTER=MagnificationModePreferenceControllerTest
Test: make RunSettingsRoboTests ROBOTEST_FILTER=AccessibilityDialogUtilsTest
Change-Id: Id09b8847cca4fce1f3fb77770a03bff53ae05855

tests/robotests/src/com/android/settings/accessibility/AccessibilityDialogUtilsTest.java

@@ -18,6 +18,7 @@ package com.android.settings.accessibility;
 
 import static com.google.common.truth.Truth.assertThat;
 
+import android.app.Dialog;
 import android.content.Context;
 
 import androidx.appcompat.app.AlertDialog;
@@ -58,4 +59,14 @@ public class AccessibilityDialogUtilsTest {
         assertThat(AccessibilityDialogUtils.updateSoftwareShortcutInDialog(mContext,
                 dialog)).isFalse();
     }
+
+    @Test
+    public void showDialog_createCustomDialog_isShowing() {
+        final Dialog dialog = AccessibilityDialogUtils.createCustomDialog(mContext,
+                "Title", /* customView= */ null, "positiveButton", /* positiveListener= */ null,
+                "negativeButton", /* negativeListener= */ null);
+        dialog.show();
+
+        assertThat(dialog.isShowing()).isTrue();
+    }
 }