docs: Removed statement that ART does not implement compacting garbage collection.

behavior changes, system enhancements, and bug fixes. This document highlights

some of the key changes that you should be understand and account for in your apps.</p>

<p>f you have previously published an app for Android, be aware that your app

<p>If you have previously published an app for Android, be aware that your app

  might be affected by these changes in Android 5.0.</p>

  <li>You use development tools that generate non-standard code (such as some

      obfuscators).</li>

  <li>You use techniques that are incompatible with compacting garbage

      collection. (ART does not currently implement compacting GC, but

      compacting GC is under development in the Android Open Source

      Project.)</li>

      collection.</li>

</ul>