Taken from Android.gitignore https://github.com/github/gitignore/blob/master/Android.gitignore
# System files
.DS_Store
# Built application files
*.apk
*.ap_
# Files for the Dalvik VM
*.dex
# Java class files
*.class
# Generated files
bin
gen
out
# 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
.idea