Enable Assist Gesture Settings to launch from action intent

Bug: 62540322

Test: adb shell am start -a android.settings.ASSIST_GESTURE_SETTINGS

Change-Id: I0aa0cc3ba87412626f6c24639efdd5e622b995e7
diff --git a/src/com/android/settings/Settings.java b/src/com/android/settings/Settings.java
index 38b6e1b..ab03c58 100644
--- a/src/com/android/settings/Settings.java
+++ b/src/com/android/settings/Settings.java
@@ -32,6 +32,7 @@
     /*
     * Settings subclasses for launching independently.
     */
+    public static class AssistGestureSettingsActivity extends SettingsActivity { /* empty */}
     public static class BluetoothSettingsActivity extends SettingsActivity { /* empty */ }
     public static class SimSettingsActivity extends SettingsActivity { /* empty */ }
     public static class TetherSettingsActivity extends SettingsActivity { /* empty */ }