From http://envyandroid.com/archives/1069/gitignore-android-studio Android Studio .gitignore

new_gist_file_0

.DS_Store
 
# built application files
*.apk
*.ap_
  
# files for the dex VM
*.dex
  
# Java class files
*.class
  
# generated files
bin/
gen/
  
# Local configuration file (sdk path, etc)
local.properties
  
# Eclipse project files
.classpath
.project
  
# Android Studio
.idea/
.gradle
gradle
/*/local.properties
/*/out
/*/*/build
build
/*/*/production
*.iml
*.iws
*.ipr
*~
*.swp