Remove apps VPN mode option for Android 4.4

mobile/src/main/res/values-v21/strings.xml

@@ -1,4 +0,0 @@
-<?xml version="1.0" encoding="utf-8"?>
-<resources>
-    <string name="proxied_apps_summary">@string/proxied_apps_summary_v21</string>
-</resources>

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

@@ -50,8 +50,7 @@
   <string name="route_entry_gfwlist">GFW List</string>
   <string name="route_entry_chinalist">China List</string>
   <string name="proxied_apps">Apps VPN mode</string>
-  <string name="proxied_apps_summary">Configure VPN mode for selected apps, not available on Android 4.x</string>
-  <string name="proxied_apps_summary_v21">Configure VPN mode for selected apps</string>
+  <string name="proxied_apps_summary">Configure VPN mode for selected apps</string>
   <string name="on">On</string>
   <string name="bypass_apps">Bypass Mode</string>
   <string name="bypass_apps_summary">Enable this option to bypass selected apps</string>

mobile/src/main/scala/com/github/shadowsocks/ProfileConfigFragment.scala

@@ -66,12 +66,14 @@ class ProfileConfigFragment extends PreferenceFragment with OnMenuItemClickListe
       findPreference(Key.password).setSummary("\u2022" * 32)
     }
     isProxyApps = findPreference(Key.proxyApps).asInstanceOf[SwitchPreference]
-    isProxyApps.setEnabled(Utils.isLollipopOrAbove && app.usingVpnMode)
-    isProxyApps.setOnPreferenceClickListener(_ => {
-      startActivity(new Intent(getActivity, classOf[AppManager]))
-      isProxyApps.setChecked(true)
-      false
-    })
+    if (Build.VERSION.SDK_INT < 21) isProxyApps.getParent.removePreference(isProxyApps) else {
+      isProxyApps.setEnabled(app.usingVpnMode)
+      isProxyApps.setOnPreferenceClickListener(_ => {
+        startActivity(new Intent(getActivity, classOf[AppManager]))
+        isProxyApps.setChecked(true)
+        false
+      })
+    }
     plugin = findPreference(Key.plugin).asInstanceOf[IconListPreference]
     pluginConfigure = findPreference(Key.pluginConfigure).asInstanceOf[EditTextPreference]
     plugin.unknownValueSummary = getString(R.string.plugin_unknown)