Set hint on TextInputLayout (#1962)

Set hint on TextInputLayout instead of EditText so that it animates properly when you start typing.

From documentation:
* The hint should be set on the TextInputLayout, rather than the EditText. If a hint is specified
 * on the child EditText in XML, the TextInputLayout might still work correctly; TextInputLayout
 * will use the EditText's hint as its floating label. However, future calls to modify the hint will
 * not update TextInputLayout's hint.

input/src/main/java/com/afollestad/materialdialogs/input/DialogInputExt.kt

@@ -159,7 +159,7 @@ private fun MaterialDialog.styleInput(
   val resources = windowContext.resources
   val editText = getInputField()
 
-  editText.hint = hint ?: if (hintRes != null) resources.getString(hintRes) else null
+  getInputLayout().hint = hint ?: if (hintRes != null) resources.getString(hintRes) else null
   editText.inputType = inputType
   editText.maybeSetTextColor(
       windowContext,