title: Reduce the Size of the Android Source Repository .repo Directory
body: <p>I have been switching between several branches of the Android source code with the commands like:</p>
  
  <pre><code>repo init -u https://android.googlesource.com/platform/manifest -b android-4.4_r1.2
  repo sync
  </code></pre>
  
  <p>The most recent tag was <code>android-5.0.0_r2</code>.  I noticed my .repo directory is now 30 GB in size.  Is that the expected size?  If not, then I'm speculating I have history from the other branches/tags I've used stored in the .repo directory.</p>
  
  <p>Is there a way to reduce the size of the .repo directory?  I would like to limit to only the source/objects/images/etc. I need for the particular branch I'm working on.  HDD space is more important to me than download time.</p>
  
  <p>I see <code>git gc</code> is used on .git repositories, but that doesn't work in this case.  Is there an equivalent for .repo repositories? </p>
  
  <p>Note:  I did try <code>repo prune</code>, but that did not reduce the size of the .repo directory.</p>