Implement Restore Revision dialog Android

[yaelirub]

For discovery history - #10008, #9812
If the post has local changes and a remote autosave, we are going to show a dialog to the user.
This issue is for implementing the design for this dialog.

Matching iOS Issue:

wordpress-mobile/WordPress-iOS#12141

[yaelirub]

@osullivanchris, can you please share the proposed copy for this?