Don't access margin directly in QuickContactActivity indicator

Bug 7536213

Change-Id: I926f12f917ef3a3a01777536fbd3f2d9193d9071
diff --git a/src/com/android/contacts/quickcontact/QuickContactActivity.java b/src/com/android/contacts/quickcontact/QuickContactActivity.java
index 3e2a364..f8d4405 100644
--- a/src/com/android/contacts/quickcontact/QuickContactActivity.java
+++ b/src/com/android/contacts/quickcontact/QuickContactActivity.java
@@ -635,12 +635,7 @@
             final RelativeLayout.LayoutParams layoutParams =
                     (RelativeLayout.LayoutParams) mSelectedTabRectangle.getLayoutParams();
             final int width = layoutParams.width;
-            final int margin = (int) ((position + positionOffset) * width);
-            if (mSelectedTabRectangle.isLayoutRtl()) {
-                layoutParams.rightMargin = margin;
-            } else {
-                layoutParams.leftMargin = margin;
-            }
+            layoutParams.setMarginStart((int) ((position + positionOffset) * width));
             mSelectedTabRectangle.setLayoutParams(layoutParams);
         }
     }