Support margins for API levels pre-17

res/layout/text_file_preview.xml

@@ -17,15 +17,17 @@
 
 -->
 <ScrollView xmlns:android="http://schemas.android.com/apk/res/android"
-    android:layout_height="match_parent"
-    android:layout_width="match_parent"
-    android:fillViewport="true">
+            android:layout_width="match_parent"
+            android:layout_height="match_parent"
+            android:fillViewport="true">
 
     <TextView
         android:id="@+id/text_preview"
         android:layout_width="match_parent"
         android:layout_height="wrap_content"
-        android:layout_marginStart="8dp"
         android:layout_marginEnd="8dp"
-        android:visibility="gone" />
+        android:layout_marginLeft="8dp"
+        android:layout_marginRight="8dp"
+        android:layout_marginStart="8dp"
+        android:visibility="gone"/>
 </ScrollView>