[Touchpad Setting] Hide Touchpad page when there's no connected one

The option for entering page already has complete check condition.
Update the same check logic to isSeachable in setting page to hide
page when there's no touchpad connected.
Also apply check on trackpadTouchGesture.

Test: verify on device
Bug: 346497646
Flag: EXEMPT bugfix
Change-Id: I1730c7bd1fd2615dc1725ec0cc32293254e5b54a

src/com/android/settings/inputmethod/TrackpadSettings.java

@@ -56,7 +56,8 @@ public class TrackpadSettings extends DashboardFragment {
                 @Override
                 protected boolean isPageSearchEnabled(Context context) {
                     return FeatureFlagUtils
-                            .isEnabled(context, FeatureFlagUtils.SETTINGS_NEW_KEYBOARD_TRACKPAD);
+                            .isEnabled(context, FeatureFlagUtils.SETTINGS_NEW_KEYBOARD_TRACKPAD)
+                            && NewKeyboardSettingsUtils.isTouchpad();
                 }
             };
 }

src/com/android/settings/inputmethod/TrackpadTouchGestureSettings.java

@@ -58,7 +58,8 @@ public class TrackpadTouchGestureSettings extends DashboardFragment {
                     return FeatureFlagUtils
                             .isEnabled(
                                     context,
-                                    FeatureFlagUtils.SETTINGS_NEW_KEYBOARD_TRACKPAD_GESTURE);
+                                    FeatureFlagUtils.SETTINGS_NEW_KEYBOARD_TRACKPAD_GESTURE)
+                            && NewKeyboardSettingsUtils.isTouchpad();
                 }
             };
 }

src/com/android/settings/inputmethod/TrackpadTouchGestureSettingsController.java

@@ -31,6 +31,7 @@ public class TrackpadTouchGestureSettingsController extends BasePreferenceContro
     public int getAvailabilityStatus() {
         boolean isFeatureOn = FeatureFlagUtils
                 .isEnabled(mContext, FeatureFlagUtils.SETTINGS_NEW_KEYBOARD_TRACKPAD_GESTURE);
-        return isFeatureOn ? AVAILABLE : CONDITIONALLY_UNAVAILABLE;
+        boolean isTouchpad = NewKeyboardSettingsUtils.isTouchpad();
+        return (isFeatureOn && isTouchpad) ? AVAILABLE : CONDITIONALLY_UNAVAILABLE;
     }
 }