Android Support (#166)

1. Add vpnservice tauri plugin for android.
2. add workflow for android.
3. Easytier Core support android, allow set tun fd.

easytier-gui/src-tauri/gen/android/.gitignore

@@ -0,0 +1,19 @@
+*.iml
+.gradle
+/local.properties
+/.idea/caches
+/.idea/libraries
+/.idea/modules.xml
+/.idea/workspace.xml
+/.idea/navEditor.xml
+/.idea/assetWizardSettings.xml
+.DS_Store
+build
+/captures
+.externalNativeBuild
+.cxx
+local.properties
+key.properties
+
+/.tauri
+/tauri.settings.gradle