Rename showcase mode to lockdown mode

app/src/main/res/drawable/ic_baseline_lock_24.xml

@@ -0,0 +1,10 @@
+<vector xmlns:android="http://schemas.android.com/apk/res/android"
+    android:width="24dp"
+    android:height="24dp"
+    android:viewportWidth="24"
+    android:viewportHeight="24"
+    android:tint="?attr/colorControlNormal">
+  <path
+      android:fillColor="@android:color/white"
+      android:pathData="M18,8h-1L17,6c0,-2.76 -2.24,-5 -5,-5S7,3.24 7,6v2L6,8c-1.1,0 -2,0.9 -2,2v10c0,1.1 0.9,2 2,2h12c1.1,0 2,-0.9 2,-2L20,10c0,-1.1 -0.9,-2 -2,-2zM12,17c-1.1,0 -2,-0.9 -2,-2s0.9,-2 2,-2 2,0.9 2,2 -0.9,2 -2,2zM15.1,8L8.9,8L8.9,6c0,-1.71 1.39,-3.1 3.1,-3.1 1.71,0 3.1,1.39 3.1,3.1v2z"/>
+</vector>

app/src/main/res/values/strings.xml

@@ -13,8 +13,9 @@
     <string name="title_activity_settings">SettingsActivity</string>
 
     <!-- Preference Titles -->
-    <string name="showcase_mode_pref">Showcase mode</string>
-    <string name="showcase_mode_desc">Showcase mode prevent manager to do action on modules</string>
+    <!-- Note: Lockdown mode used to be called showcase mode -->
+    <string name="showcase_mode_pref">Lockdown mode</string>
+    <string name="showcase_mode_desc">Lockdown mode prevent manager to do action on modules</string>
     <string name="pref_category_settings">Settings</string>
     <string name="pref_category_info">Info</string>
     <string name="show_licenses">Show licenses</string>

app/src/main/res/xml/root_preferences.xml

@@ -16,10 +16,11 @@
             app:icon="@drawable/ic_baseline_list_24"
             app:title="@string/force_dark_terminal_title" />
 
+        <!-- Note: Lockdown mode used to be called showcase mode -->
         <SwitchPreferenceCompat
             app:defaultValue="false"
             app:key="pref_showcase_mode"
-            app:icon="@drawable/ic_baseline_monitor_24"
+            app:icon="@drawable/ic_baseline_lock_24"
             app:title="@string/showcase_mode_pref"
             app:summary="@string/showcase_mode_desc"/>