TextView bold via xml file?

I have a project in which I have the following TextView :

<TextView
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:textStyle="bold"
    android:text="@string/app_name"
    android:layout_gravity="center" 
/>

So, I'm guessing you need to use android:textStyle

Example:

use: android:textStyle="bold"

 <TextView
    android:id="@+id/txtVelocidade"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_above="@+id/txtlatitude"
    android:layout_centerHorizontal="true"
    android:layout_marginBottom="34dp"
    android:textStyle="bold"
    android:text="Aguardando GPS"
    android:textAppearance="?android:attr/textAppearanceLarge" />

just use

android:textStyle="bold"