Fix assert not working

mobile/src/main/java/com/github/shadowsocks/plugin/PluginManager.kt

@@ -134,7 +134,7 @@ object PluginManager {
     private fun initNative(options: PluginOptions): String? {
         val providers = app.packageManager.queryIntentContentProviders(
                 Intent(PluginContract.ACTION_NATIVE_PLUGIN, buildUri(options.id)), 0)
-        assert(providers.size == 1)
+        check(providers.size == 1)
         val uri = Uri.Builder()
                 .scheme(ContentResolver.SCHEME_CONTENT)
                 .authority(providers[0].providerInfo.authority)
@@ -154,7 +154,7 @@ object PluginManager {
         out.putString(PluginContract.EXTRA_OPTIONS, options.id)
         val result = cr.call(uri, PluginContract.METHOD_GET_EXECUTABLE, null, out)
                 .getString(PluginContract.EXTRA_ENTRY)
-        assert(File(result).canExecute())
+        check(File(result).canExecute())
         return result
     }
 
@@ -173,7 +173,7 @@ object PluginManager {
             do {
                 val path = cursor.getString(0)
                 val file = File(pluginDir, path)
-                assert(file.absolutePath.startsWith(pluginDirPath))
+                check(file.absolutePath.startsWith(pluginDirPath))
                 cr.openInputStream(uri.buildUpon().path(path).build()).use { inStream ->
                     file.outputStream().use { outStream -> inStream.copyTo(outStream) }
                 }