title: Invalid color value ?android:colorControlNormal
body: <p>I have a drawable resource file like this:</p>
  <pre><code>&lt;vector xmlns:android=&quot;http://schemas.android.com/apk/res/android&quot;
      xmlns:tools=&quot;http://schemas.android.com/tools&quot;
      android:width=&quot;24dp&quot;
      android:height=&quot;24dp&quot;
      android:viewportWidth=&quot;24.0&quot;
      android:viewportHeight=&quot;24.0&quot;&gt;
      &lt;path
          android:fillColor=&quot;?android:colorControlNormal&quot;
          android:pathData=&quot;M9,11L7,11v2h2v-2zM13,11h-2v2h2v-2zM17,11h-2v2h2v-2zM19,4h-1L18,2h-2v2L8,4L8,2L6,2v2L5,4c-1.11,0 -1.99,0.9 -1.99,2L3,20c0,1.1 0.89,2 2,2h14c1.1,0 2,-0.9 2,-2L21,6c0,-1.1 -0.9,-2 -2,-2zM19,20L5,20L5,9h14v11z&quot;
          tools:targetApi=&quot;lollipop&quot; /&gt;
  &lt;/vector&gt;
  </code></pre>
  <p>On Gradle Build, Error is as follows:</p>
  <pre><code>Invalid color value ?android:colorControlNormal
  at com.android.ide.common.resources.MergedResourceWriter$FileGenerationWorkAction.run
  </code></pre>
  <p><strong>What I tried:</strong>  I changed it to <code>?attr/colorControlNormal</code>, but still same error
  I am stuck at this. Can somebody help?</p>