Pin: add LockScreenConfig and address PR reviews

appconfig/src/main/kotlin/io/element/android/appconfig/LockScreenConfig.kt

@@ -0,0 +1,35 @@
+/*
+ * Copyright (c) 2023 New Vector Ltd
+ *
+ * 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 io.element.android.appconfig
+
+object LockScreenConfig {
+
+    /**
+     * Whether the LockScreen is mandatory or not.
+     */
+    const val IS_MANDATORY: Boolean = false
+
+    /**
+     * Some PINs are blacklisted.
+     */
+    val PIN_BLACKLIST = listOf("0000", "1234")
+
+    /**
+     * The size of the PIN.
+     */
+    const val PIN_SIZE = 4
+}