title: TextView Font not applied on execution
body: <p>I selected <code>android:fontFamily="casual"</code> into a TxtView, in editor it's ok but not when launching app (not emulated, on my phone)</p>
  
  <p>Why?</p>
  
  <p>my layout file: </p>
  
  <pre><code>&lt;?xml version="1.0" encoding="utf-8"?&gt;
  &lt;android.support.constraint.ConstraintLayout  xmlns:android="http://schemas.android.com/apk/res/android"
  xmlns:app="http://schemas.android.com/apk/res-auto"
  xmlns:tools="http://schemas.android.com/tools"
  android:layout_width="match_parent"
  android:layout_height="match_parent"
  android:background="@drawable/r1"
  android:visibility="visible"
  tools:context="com.example.dev_1.myapplication1.MainActivity"
  tools:layout_editor_absoluteY="81dp"
  tools:layout_editor_absoluteX="0dp"&gt;
  
  &lt;TextView
      android:id="@+id/textView2"
      android:layout_width="0dp"
      android:layout_height="wrap_content"
      android:layout_marginStart="16dp"
      android:layout_marginTop="60dp"
      android:layout_weight="0.04"
      android:fontFamily="casual"
      android:text="This is my text"
      android:textAlignment="center"
      android:textColor="@android:color/holo_green_light"
      android:textSize="30sp"
      android:textStyle="bold"
      app:layout_constraintTop_toTopOf="parent"&gt;
  
  &lt;/TextView&gt;
  
  &lt;Button
      android:id="@+id/button1"
      style="@android:style/Widget.Holo.Light.Button"
      android:layout_width="220dp"
      android:layout_height="wrap_content"
      android:layout_marginBottom="50dp"
      android:onClick="func_fiche1"
      android:text="xxxxx"
      android:textColor="@android:color/white"
      app:layout_constraintBottom_toTopOf="@+id/button2"
      app:layout_constraintHorizontal_bias="0.502"
      app:layout_constraintLeft_toLeftOf="parent"
      app:layout_constraintRight_toRightOf="parent"
      tools:layout_constraintBottom_creator="1"
      tools:layout_constraintLeft_creator="1"
      tools:layout_constraintRight_creator="1" /&gt;
  
  &lt;Button
      android:id="@+id/button2"
      style="@android:style/Widget.Holo.Light.Button"
      android:layout_width="220dp"
      android:layout_height="wrap_content"
      android:layout_marginBottom="50dp"
      android:onClick="func_fiche2"
      android:text="xxxxxx"
      android:textColor="@android:color/white"
      app:layout_constraintBottom_toTopOf="@+id/button3"
      app:layout_constraintHorizontal_bias="0.497"
      app:layout_constraintLeft_toLeftOf="parent"
      app:layout_constraintRight_toRightOf="parent"
      tools:layout_constraintBottom_creator="1"
      tools:layout_constraintLeft_creator="1"
      tools:layout_constraintRight_creator="1" /&gt;
  
  &lt;Button
      android:id="@+id/button3"
      style="@android:style/Widget.Holo.Light.Button"
      android:layout_width="220dp"
      android:layout_height="wrap_content"
      android:layout_marginBottom="39dp"
      android:onClick="func_fiche3"
      android:text="xxxxx"
      android:textColor="@android:color/white"
      android:textSize="18sp"
      app:layout_constraintBottom_toBottomOf="parent"
      app:layout_constraintHorizontal_bias="0.497"
      app:layout_constraintLeft_toLeftOf="parent"
      app:layout_constraintRight_toRightOf="parent"
      tools:layout_constraintBottom_creator="1"
      tools:layout_constraintLeft_creator="1"
      tools:layout_constraintRight_creator="1" /&gt;
  
  &lt;/android.support.constraint.ConstraintLayout&gt;
  </code></pre>
  
  <p>Android studio 2.3.3</p>
  
  <p>build.gradle: </p>
  
  <pre><code>apply plugin: 'com.android.application'
  
  android {
      compileSdkVersion 25
      buildToolsVersion "26.0.1"
      defaultConfig {
          applicationId "com.example.dev_1.myapplication1"
          minSdkVersion 19
          targetSdkVersion 25
          versionCode 1
          versionName "1.0"
          testInstrumentationRunner "android.support.test.runner.AndroidJUnitRunner"
      }
      buildTypes {
          release {
              minifyEnabled false
              proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
          }
      }
  }
  
  dependencies {
  compile fileTree(dir: 'libs', include: ['*.jar'])
  androidTestCompile('com.android.support.test.espresso:espresso- core:2.2.2', {
      exclude group: 'com.android.support', module: 'support-annotations'
  })
  compile 'com.android.support:appcompat-v7:25.3.1'
  compile 'com.android.support.constraint:constraint-layout:1.0.2'
  testCompile 'junit:junit:4.12'
  </code></pre>