Fix for header text misalignment, and remove unused layout (#386)

Author: amandle

auth/src/main/res/layout/delete_credential.xml

@@ -8,7 +8,6 @@
         <item name="android:textColorHint">@color/authui_colorPrimary</item>
         <item name="android:buttonStyle">@style/FirebaseUI.Button</item>
         <item name="android:editTextStyle">@style/FirebaseUI.EditText</item>
-        <item name="android:textViewStyle">@style/FirebaseUI.Text.BodyText</item>
         <item name="android:textColorPrimary">#FFF</item>
         <item name="android:textColor">#000</item>
     </style>