Switch gen_snapshot from Android's one to elinux's one (#82)

lib/commands/build.dart

@@ -27,7 +27,8 @@ class ELinuxBuildCommand extends BuildCommand {
   }
 }
 
-class BuildPackageCommand extends BuildSubCommand with ELinuxExtension {
+class BuildPackageCommand extends BuildSubCommand
+    with ELinuxExtension, ELinuxRequiredArtifacts {
   /// See: [BuildApkCommand] in `build_apk.dart`
   BuildPackageCommand({bool verboseHelp = false})
       : super(verboseHelp: verboseHelp) {

lib/commands/drive.dart

@@ -8,9 +8,11 @@
 import 'package:flutter_tools/src/commands/drive.dart';
 import 'package:flutter_tools/src/globals.dart' as globals;
 
+import '../elinux_cache.dart';
 import '../elinux_plugins.dart';
 
-class ELinuxDriveCommand extends DriveCommand with ELinuxExtension {
+class ELinuxDriveCommand extends DriveCommand
+    with ELinuxExtension, ELinuxRequiredArtifacts {
   ELinuxDriveCommand({bool verboseHelp = false})
       : super(
           verboseHelp: verboseHelp,

lib/commands/run.dart

@@ -13,7 +13,8 @@ import 'package:flutter_tools/src/commands/run.dart';
 import '../elinux_cache.dart';
 import '../elinux_plugins.dart';
 
-class ELinuxRunCommand extends RunCommand with ELinuxExtension {
+class ELinuxRunCommand extends RunCommand
+    with ELinuxExtension, ELinuxRequiredArtifacts {
   ELinuxRunCommand({bool verboseHelp = false})
       : super(verboseHelp: verboseHelp);