Touchpad: replace references to "trackpad" with "touchpad"

When we first added the touchpad settings we hadn't settled on whether
to refer to them as "touchpads" or "trackpads" yet. We've since settled
on "touchpad", but that's left us with some Settings code referring to
one and some to the other. Let's standardize on "touchpad" since that's
consistent with user-facing strings and the rest of the input codebase.

This CL doesn't change string identifiers, as I believe that would cause
them to get different Translation Console IDs and thus be retranslated.

Bug: 245989146
Test: m
Test: check strings and icons are still displayed correctly in the
      touchpad settings and tutorial, and that settings toggles and the
      tutorial still work
Test: atest SettingsRoboTests
Flag: EXEMPT refactor
Change-Id: I930e9fc85e09e03da3513e5f8443077fa8ea91b0

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

@@ -0,0 +1,35 @@
+/*
+ * Copyright 2024 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.android.settings.inputmethod;
+
+import android.content.Context;
+import android.hardware.input.InputSettings;
+
+import com.android.settings.core.BasePreferenceController;
+
+public class TouchpadGesturesDisabledFooterPreferenceController extends BasePreferenceController {
+
+    public TouchpadGesturesDisabledFooterPreferenceController(Context context, String key) {
+        super(context, key);
+    }
+
+    @Override
+    public int getAvailabilityStatus() {
+        return InputSettings.useTouchpadSystemGestures(mContext) ? CONDITIONALLY_UNAVAILABLE
+                : AVAILABLE;
+    }
+}