title: Android Studio Git: having to commit everytime i change branch
body: <p>If I checkout a branch, make no changes but gradle does a full rebuild of the project, when i go to checkout a different branch, it git gives me a error in the terminal saying changes have been made to the</p>
  
  <pre><code>modified:   .idea/workspace.xml
  modified:   app/app.iml
  </code></pre>
  
  <p>even though i didnt make any changes, they were done android studio, and it says everytime that I have to commit in order to checkout another branch.
  are these changes important ? can I just remove/revert or dont save the changes? or do I have to commit every time?
  Can I just add these two files to my gitignore?
  As I dont actually know what changes it making so dont know what to put in the commit message. 
  are they just changes in the project settings? can I disregard them ?</p>