Support accessibility shortcut secondary action (10/n)

Integrate with Talkback enabled and change the behavior as below:
1. Show 3-finger swipe up from bottom summary
2. Show 3-finger icons for edit shortcut dialog
3. Dismiss the running the edit shortcut dialog

Bug: 142530063
Bug: 142531156
Bug: 147989432
Test: make RunSettingsRoboTests2
Change-Id: I2f34b8eebfdc5a385d72402e95a8b1d0bde4a428

src/com/android/settings/accessibility/AccessibilityUtil.java

@@ -24,6 +24,7 @@ import android.content.Context;
 import android.os.Build;
 import android.provider.Settings;
 import android.text.TextUtils;
+import android.view.accessibility.AccessibilityManager;
 
 import androidx.annotation.IntDef;
 import androidx.annotation.NonNull;
@@ -139,6 +140,12 @@ final class AccessibilityUtil {
                 == NAV_BAR_MODE_GESTURAL;
     }
 
+    /** Determines if a touch explore is being used. */
+    public static boolean isTouchExploreEnabled(Context context) {
+        final AccessibilityManager am = context.getSystemService(AccessibilityManager.class);
+        return am.isTouchExplorationEnabled();
+    }
+
     /**
      * Gets the corresponding fragment type of a given accessibility service.
      *