Hi @Sakshi Sharma,
You will need sites.readall permission to view the PDF file from SharePoint in android. It's same as the permission on other environment. For the samples in MSAL you can refer to the document
And since our forum is focus on C#. You can raise a new ticket in techcommunity. You might get some more professional advice there.
If the answer is helpful, please click "Accept Answer" and kindly upvote it. If you have extra questions about this answer, please click "Comment".
Note: Please follow the steps in our documentation to enable e-mail notifications if you want to receive the related email notification for this thread.