fix: TabBar with scrollEnable to take into consideration the content margins

[andreibarabas]

If you want to use a custom TabBar like

<TabBar
      {...tabBarProps}
      scrollEnabled={true}
      contentContainerStyle={{marginLeft: 14}}
/>

currently, the last tab will be cut with 14px, as it does not take into consideration these kind of spacing.

This PR fixes that.

Motivation

The last tab item is cut with with the amount you put as padding / margin to the contentContainer.

Test plan

Let me know if you need any screenshots, but should be straitforward