title: MaterialDatePicker shows current date instead of needed
body: <p>Using <a href="https://ahsensaeed.com/android-material-design-library-date-picker-dialog/" rel="noreferrer">MaterialDatePicker</a> I want to show required date and give an opportunity to select another. But when a DatePicker appears it shows current date instead of specified.</p>
  
  <p>I plug the library: <code>implementation 'com.google.android.material:material:1.2.0-alpha06'</code> (or 1.1.0). </p>
  
  <p>Then override <code>AppTheme</code> in <code>styles.xml</code>:</p>
  
  <pre><code>&lt;style name="AppTheme" parent="Theme.MaterialComponents.Light"&gt;
  </code></pre>
  
  <p>And now can show DatePicker.</p>
  
  <pre><code>val now = Calendar.getInstance()
  now[Calendar.YEAR] = 2020
  now[Calendar.MONTH] = 10
  now[Calendar.DAY_OF_MONTH] = 1
  val builder = MaterialDatePicker.Builder.datePicker()
  builder.setSelection(now.timeInMillis)
  
  val picker = builder.build()
  fragmentManager?.let { picker.show(it, MaterialDatePicker::class.java.simpleName) }
  </code></pre>
  
  <p>This is a result. I want to show 1st November, but it shows 7th May.</p>
  
  <p><a href="https://i.stack.imgur.com/RkzYb.png" rel="noreferrer"><img src="https://i.stack.imgur.com/RkzYb.png" alt="enter image description here"></a></p>
  
  <p>UPDATE 1</p>
  
  <p>As written in above link, we can use <code>CalendarConstraints.Builder</code>:</p>
  
  <pre><code>...
  val constraintsBuilder = CalendarConstraints.Builder()
  constraintsBuilder.setStart(now.timeInMillis)
  constraintsBuilder.setEnd(now.timeInMillis)
  
  val builder = MaterialDatePicker.Builder.datePicker()
  builder.setCalendarConstraints(constraintsBuilder.build())
  builder.setSelection(now.timeInMillis)
  ...
  </code></pre>
  
  <p>This will show required date, we can select another day, but we cannot scroll months.</p>
  
  <p><a href="https://i.stack.imgur.com/jUMzS.png" rel="noreferrer"><img src="https://i.stack.imgur.com/jUMzS.png" alt="enter image description here"></a></p>
  
  <p>UPDATE 2</p>
  
  <p>I suppose this is a bug of a new Android DatePicker. So I have to select well-known library <a href="https://github.com/wdullaer/MaterialDateTimePicker" rel="noreferrer">https://github.com/wdullaer/MaterialDateTimePicker</a>. It selects a specified date right and doesn't require changing an original theme.</p>
  
  <p><a href="https://i.stack.imgur.com/2yIhU.png" rel="noreferrer"><img src="https://i.stack.imgur.com/2yIhU.png" alt="enter image description here"></a></p>