Fix DrawBorder now updating color for left border, drawing it with old color

Summary: There is a small bug in DrawBorder where we forget updating color for a left border, which makes the border draw with whatever color was previously set to the Paint. This diff fixes it by updating the color.

Reviewed By: ahmedre

Differential Revision: D2779511

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

@@ -237,6 +237,7 @@ import com.facebook.csslayout.Spacing;
     float rightOfTheLeft = getLeft() + leftWidth;
     int leftColor = resolveBorderColor(BORDER_LEFT_COLOR_SET, mBorderLeftColor, defaultColor);
     if (Color.alpha(leftColor) != 0 && leftWidth != 0) {
+      PAINT.setColor(leftColor);
       canvas.drawRect(getLeft(), bottomOfTheTop, rightOfTheLeft, topOfTheBottom, PAINT);
     }