title: Widget icon not updating
body: <p>I've defined an upload_widget.png file for my app widget, and declared it as below in my AndroidManifest.xml. It worked fine when I first created it, but I've now made a change to the .png image files (in each of /drawable folders), synchronised the files in Android Studio, but the widget icon is not reflecting the new .png files when I re-test the app on my Galaxy S4. 
  When I long-press on the screen (I'm using Nova Launcher) and select "add widget" I see the correct icon in the "Choose Widget" list, but when I select it I get a different icon on the launcher - i.e. the old icon. When I run the app in a Nexus 5 emulator I get the same problem.
  Any ideas??</p>
  
  <pre><code>&lt;receiver android:name=".UploadWidget" android:icon="@drawable/upload_widget" &gt;
      &lt;intent-filter&gt;
          &lt;action android:name="android.appwidget.action.APPWIDGET_UPDATE" /&gt;
      &lt;/intent-filter&gt;
  
      &lt;meta-data
          android:name="android.appwidget.provider"
          android:resource="@xml/upload_widget_info" /&gt;
  &lt;/receiver&gt;
  </code></pre>
  
  <p><strong>UPDATE</strong></p>
  
  <p>Here is upload_widget_info:</p>
  
  <pre><code>&lt;?xml version="1.0" encoding="utf-8"?&gt;
  &lt;appwidget-provider xmlns:android="http://schemas.android.com/apk/res/android"
      android:minWidth="40dp" android:minHeight="40dp" android:updatePeriodMillis="86400000"
      android:previewImage="@drawable/example_appwidget_preview"
      android:initialLayout="@layout/upload_widget" android:resizeMode="horizontal|vertical"
      android:widgetCategory="home_screen|keyguard"
      android:initialKeyguardLayout="@layout/upload_widget"&gt;&lt;/appwidget-provider&gt;
  </code></pre>