title: How to change indices in a room migration?
body: <p>The old Entity as below:</p>
  
  <pre><code>@Entity(tableName = "d_course",
      foreignKeys = @ForeignKey(entity = DUser.class, parentColumns = "id", childColumns = "studio"),
      indices = @Index(value = "studio"))
  </code></pre>
  
  <p>The new Entity as below:</p>
  
  <pre><code>@Entity(tableName = "d_course",
      foreignKeys = @ForeignKey(entity = DUser.class, parentColumns = "id", childColumns = "studio"),
      indices = @Index(value = {"id", "studio"}))
  </code></pre>
  
  <p>How do I migrate this <strong>indices</strong> change.</p>