BottomBar added on Exchange Rates Screen

[shamim-emon]

Pull request (PR) checklist

Please check if your pull request fulfills the following requirements:

• I've read the Contribution Guidelines and my PR doesn't break the rules.
• I've read and understand the Developer Guidelines.
• I confirm that I've run the code locally and everything works as expected.
• My PR includes only the necessary changes to fix the issue (i.e., no unnecessary files or lines of code are changed).
• 🎬 I've attached a screen recording of using the new code to the next paragraph (if applicable).

What's changed?

• I've added Bottom bar (having navigation back button) on Exchange Rates screen

Before(Left) | After(Right)

What may go wrong if we merge your PR?

• N/A

In what cases won't your code work?

• N/A

Does this PR close any GitHub issues? (do not delete)

• Closes [FEATURE] Navigation Back Button In Exchange Rates  #3504

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