feat: add Android ARMv8 (aarch64) build support

- Initialize Tauri Android project structure (gen/android)
- Fix desktop_dir() unavailability on Android in file_explorer.rs and serial.rs
- Fix minimize/maximize/unmaximize unavailability on Android in window.rs
- Remove updater:default permission from default capabilities (not available on Android)
- Update .gitignore for Android build artifacts
- Successfully builds APK for aarch64-linux-android target

src-tauri/gen/android/gradle/wrapper/gradle-wrapper.properties

@@ -0,0 +1,6 @@
+#Tue May 10 19:22:52 CST 2022
+distributionBase=GRADLE_USER_HOME
+distributionUrl=https\://services.gradle.org/distributions/gradle-8.14.3-bin.zip
+distributionPath=wrapper/dists
+zipStorePath=wrapper/dists
+zipStoreBase=GRADLE_USER_HOME