Simplify width calculation in RCTText

Summary:
getLayoutWidth is the same as right - left, and since we have right
and left, we can save a method call.

Reviewed By: sriramramani

Differential Revision: D3010697

ReactAndroid/src/main/java/com/facebook/react/flat/RCTText.java

@@ -173,7 +173,7 @@ import com.facebook.react.uimanager.annotations.ReactProp;
       mDrawCommand = new DrawTextLayout(new BoringLayout(
           mText,
           PAINT,
-          (int) getLayoutWidth(),
+          (int) (right - left),
           mAlignment,
           mSpacingMult,
           mSpacingAdd,