title: AndroidStudio: add virtual folder in gradle
body: <p>I use the build.gradle file to collect several folders on my computer in my app's asset folder:</p>
  
  <pre><code>sourceSets {
      main {
          assets.srcDirs = ['../someFolder/', 'src/main/assets']
      }
  }
  </code></pre>
  
  <p>This leads to my asset folder having the files of <code>someFolder</code> and the "original" asset folder:</p>
  
  <pre><code>//The "physical" folders
  
  ../someFolder
    |- file1.txt
    |- file2.txt
    |- file3.txt
  src/main/assets
    |- asset1.txt
  
  //...become this:
  
  assets
    |- file1.txt
    |- file2.txt
    |- file3.txt
    |- asset1.txt 
  </code></pre>
  
  <p>How can I redirect the paths in gradle so that my asset folder contains a folder "someFolder" with all the files from <code>someFolder</code>, e.g:</p>
  
  <pre><code>assets
    |- someFolder
    |--- file1.txt
    |--- file2.txt
    |--- file3.txt
    |- asset1.txt 
  </code></pre>