Jay Swaminarayan! @dan
Something that I have learnt a hard way, after a week long troubleshooting was surprising silly, at least for you or other experienced members of fusionauth community.
However, little I knew the security concerns of the browser, It turns out that,
-
A javascript cannot directly redirect to any com.android.app:/redirect_uri.
-
There must be a User Manual Interactivity for the Redirect to complete, A Button Click or Ancher Link Click
-
That was the Reason Chrome Cancelled the redirect from FusionAuth Screen
What I could find,
One of the reasons, that there are consent screens,

Basically Allow Button, redirect back to the app.
My conclusion:
- It would be Great if this Consent Screen Mechanism is available for Native Redirects after 1st Authorization within FusionAuth.
- Time-being I have made a Consent Screen of my own, which is the redirect_uri and than in turn that redirects back to the APP.

I don't know, if what I am doing is best practice or was there something else I should have done, at least this is working for me as now.
Thank you once again.
PS: There is another issue, calling /api/logout?global=true&refreshToken={refresh_token} only signs out of the app, but doesn't signout from the FusionAuth completely, making it redirecting back to the App instead of the Login Screen?