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