Add Gradle wrapper and configuration files for Android project

- Created gradle-wrapper.properties to specify Gradle distribution details.
- Added gradlew and gradlew.bat scripts for executing Gradle tasks.
- Introduced settings.gradle for project configuration and dependency management.
- Added assetlinks.json for Android App Links support.

tx-android/.gitignore

@@ -0,0 +1,33 @@
+# Gradle
+.gradle/
+build/
+**/build/
+gradle-app.setting
+!gradle-wrapper.jar
+
+# Android Studio
+.idea/
+*.iml
+local.properties
+.navigation/
+.externalNativeBuild/
+.cxx/
+
+# Signing
+keystore.properties
+*.jks
+*.keystore
+*.p12
+*.pem
+
+# Generated
+captures/
+outputs/
+*.apk
+*.aab
+*.ap_
+
+# Logs / OS
+*.log
+Thumbs.db
+.DS_Store