Fix initialPage prop of Tabs component for IOS

[VahidBo]

Motivation

The initialPage prop of Tabs component is not working in IOS devices.

Test Plan

For this code:

...
        <Tabs initialPage={2}>
          <Tab heading="Tab1">
            <Tab1 />
          </Tab>
          <Tab heading="Tab2">
            <Tab2 />
          </Tab>
          <Tab heading="Tab3">
            <Tab3 />
          </Tab>
        </Tabs>
...

Before fixing this issue, the content of the initial tab (in this case Tab3) will render but the first tab is showing and then nothing will be showing in the tab. After this fixing, the right tab will show in the page. In this way the initialPage prop will work properly in IOS devices.
This commit will also fix #1318 and #1010.

[akhil-ga]

@VahidBo tried your fix. Don't think the issue is fixed.

Gif

[tiberiumihai]

This is because InteractionManager.runAfterInteractions(f) happen to sometimes never call f. Specially in DEV mode.

I've added a PR here: #1376

[SupriyaKalghatgi]

@VahidBo Are you planning to fix this PR?

[tiberiumihai]

@SupriyaKalghatgi I fixed this in #1376. It's basically the same fix as @VahidBo provided, only that is also included a fix for IteractionManager which happens to never call the callback sent to runAfterInteractions.

And because of this, InteractionManager.runAfterInteractions(scrollFn); never run.

You can check the whole fix in #1376.

[SupriyaKalghatgi]

@tiberiumihai Yes i have gone through it
Since @VahidBo initiated this PR, i should be asking him for fix before closing this PR

[SupriyaKalghatgi]

@VahidBo Closing this PR