android: Use GitHub gitignore template for Android

https://github.com/github/gitignore/blob/main/Android.gitignore

openvidu-android/.gitignore

@@ -1,14 +1,100 @@
+# github/gitignore/Android
+# ========================
+
+# Built application files
+*.apk
+*.aar
+*.ap_
+*.aab
+
+# Files for the ART/Dalvik VM
+*.dex
+
+# Java class files
+*.class
+
+# Generated files
+bin/
+gen/
+out/
+#  Uncomment the following line in case you need and you don't have the release build type files in your app
+# release/
+
+# Gradle files
+.gradle/
+build/
+
+# Local configuration file (sdk path, etc)
+local.properties
+
+# Proguard folder generated by Eclipse
+proguard/
+
+# Log Files
+*.log
+
+# Android Studio Navigation editor temp files
+.navigation/
+
+# Android Studio captures folder
+captures/
+
+# IntelliJ
 *.iml
-.gradle
+.idea/workspace.xml
-/local.properties
+.idea/tasks.xml
-/.idea/caches
+.idea/gradle.xml
-/.idea/libraries
+.idea/assetWizardSettings.xml
-/.idea/modules.xml
+.idea/dictionaries
-/.idea/workspace.xml
+.idea/libraries
-/.idea/navEditor.xml
+.idea/jarRepositories.xml
-/.idea/assetWizardSettings.xml
+# Android Studio 3 in .gitignore file.
-.DS_Store
+.idea/caches
-/build
+.idea/modules.xml
-/captures
+# Comment next line if keeping position of elements in Navigation Editor is relevant for you
+.idea/navEditor.xml
+
+# Keystore files
+# Uncomment the following lines if you do not want to check your keystore files in.
+#*.jks
+#*.keystore
+
+# External native build folder generated in Android Studio 2.2 and later
 .externalNativeBuild
-.cxx
+.cxx/
+
+# Google Services (e.g. APIs or Firebase)
+# google-services.json
+
+# Freeline
+freeline.py
+freeline/
+freeline_project_description.json
+
+# fastlane
+fastlane/report.xml
+fastlane/Preview.html
+fastlane/screenshots
+fastlane/test_output
+fastlane/readme.md
+
+# Version control
+vcs.xml
+
+# lint
+lint/intermediates/
+lint/generated/
+lint/outputs/
+lint/tmp/
+# lint/reports/
+
+# Android Profiling
+*.hprof
+
+
+
+# Custom ignore rules
+# ===================
+
+# IntelliJ
+.idea/deploymentTargetDropDown.xml