[Tech Debt] Remove usage of deprecated startActivityForResult & onActivityResult APIs in favour of decoupled result APIs

[parneet-guraya]

Remove usage of deprecated startActivityForResult & onActivityResult APIs in favour of decoupled result APIs.

While the underlying startActivityForResult() and onActivityResult() APIs are available on the Activity class on all API levels, Google strongly recommends using the Activity Result APIs introduced in AndroidX Activity and Fragment classes.

For more on what benefits it offers refer here https://developer.android.com/training/basics/intents/result#custom

P.S: We already have newer code using this API. Only some place that needs refactor.

[parneet-guraya]

I have done this migrations a few times. So, I'd like to work on this :)

[parneet-guraya]

Waiting for this one #5851 to merge and then I will continue.