.gitignore for Android Studio

.gitignore

# Gradle files
/gradle.properties
.gradle/

# Generated files
build/
gen/
models-gen/
bin/
out/
/Test Results*

# Crashlytics configuations
com_crashlytics_export_strings.xml

# Local configuration file
local.properties

# Gradle generated files
.gradle/

# Signing files
.signing/

# OS-specific files
.DS_Store
.DS_Store?
._*
.Spotlight-V100
.Trashes
ehthumbs.db
Thumbs.db

# User specific Intellij files
.idea/libraries/
.idea/workspace.xml
.idea/tasks.xml
.idea/.name
.idea/compiler.xml
.idea/copyright/profiles_settings.xml
.idea/encodings.xml
.idea/misc.xml
.idea/modules.xml
.idea/scopes/scope_settings.xml
.idea/vcs.xml
*.iml

# Misc.
/.metadata
/git.store

we may also use an awesome online tool to generate a gitignore
https://www.gitignore.io/