title: Float Label hint (TextInputLayout) not works with Android Data Binding
body: <p>I need create fields edit page in app. There are list of EditText for edit Contact. For each field type i have an layout. As example - for name and last name it is float labeled edit text. For facebook - simple edit text with icon. I am creating this list with Android Data Binding Library</p>
  
  <p>I've created layout</p>
  
  <p></p>
  
  <pre><code>&lt;data&gt;
  
      &lt;variable
          name="item"
          type="app.core.db.model.Field" /&gt;
  &lt;/data&gt;
  
  &lt;FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
      android:layout_width="match_parent"
      android:layout_height="wrap_content"
      android:orientation="vertical"&gt;
  
      &lt;android.support.design.widget.TextInputLayout
          android:layout_width="match_parent"
          android:layout_height="65dp"
          app:hintTextAppearance="@style/TextAppearence.App.TextInputLayout"
          app:theme="@style/EditFieldFloatLabeled"&gt;
  
          &lt;EditText
              android:layout_width="match_parent"
              android:layout_height="wrap_content"
              android:ellipsize="end"
              android:hint="@{item.getHint()}"
              android:imeOptions="actionNext"
              android:maxLines="1" /&gt;
      &lt;/android.support.design.widget.TextInputLayout&gt;
  
  &lt;/FrameLayout&gt;
  </code></pre>
  
  <p></p>
  
  <p>But float label not works. I starts commenting line by line to find out reason. Float label became work when I've commented line</p>
  
  <pre><code>android:hint="@{item.getHint()}
  </code></pre>
  
  <p>(And replace it with hardcoded text). <code>getHint()</code> returns <code>R.string.{something}</code> based on field type.</p>
  
  <p>There I've found out than programmatically setting hint produce float label disappearing. I can not use static layout (instead recycler view) because fields list can increase dynsmically (ex: I am writing phone number in field and empty Phone field inserts after it for other phone number).</p>
  
  <p>Is there way to create float label same way (by defining hint with field type)?</p>