Persist dev option reboot dialog on rotation.

Use a ViewModel to store reboot dialog fragment state on rotations.

Test: locally verified rotations on few dev options that use the reboot fragment
Test: atest
com.android.settings.development.RebootConfirmationDialogFragmentTest
--iterations 25 (Passed)
Bug: 356273849
Flag: EXEMPT bug fix

Change-Id: I154170ea5fa91bcbec32af43853c5f99f8e8253d

src/com/android/settings/development/RebootConfirmationDialogViewModel.java

@@ -0,0 +1,57 @@
+/*
+ * Copyright (C) 2025 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.development;
+
+import androidx.annotation.Nullable;
+import androidx.lifecycle.ViewModel;
+
+/**
+ * {@link ViewModel} for the reboot confirmation dialog.
+ *
+ * This class holds the data necessary to display a confirmation dialog for reboots.
+ */
+public class RebootConfirmationDialogViewModel extends ViewModel {
+    @Nullable
+    private RebootConfirmationDialogHost mHost = null;
+    private int mMessageId;
+    private int mCancelButtonId;
+
+    @Nullable
+    public RebootConfirmationDialogHost getHost() {
+        return mHost;
+    }
+
+    public void setHost(RebootConfirmationDialogHost mHost) {
+        this.mHost = mHost;
+    }
+
+    public int getMessageId() {
+        return mMessageId;
+    }
+
+    public void setMessageId(int mMessageId) {
+        this.mMessageId = mMessageId;
+    }
+
+    public int getCancelButtonId() {
+        return mCancelButtonId;
+    }
+
+    public void setCancelButtonId(int mCancelButtonId) {
+        this.mCancelButtonId = mCancelButtonId;
+    }
+}