title: how to add "android.library=true" with the "android update" command
body: <p>I want to build an Android project from command-line and want to add the <code>android.library=true</code> flag to the project.properties. I also want to do it with he the <code>android</code> command from the sdk and NOT add it manually to the file, because file- and property-names could change. </p>
  
  <p>the command <code>android update lib-project -p PATH</code> does not add this flag anymore.</p>
  
  <p>the command <code>android create lib-project ...</code> does "add" this flag, but overrides some files like string resources</p>
  
  <p>So my question is: it is possible with the <code>android</code> tool to make a project.properties that has this android.library flag set to true, and doesn't do much more?</p>
  
  <p>What is the difference between <code>android update project</code> and <code>android update lib-project</code> beside I cannot use some flags in lib-project? </p>