Removed the restriction popup from PS variant which was showing at start.

[MohitMaliFtechiz]

• Since now we have a way to load the sideloaded zim files in the application(Added the file picker in play store variant for move or copy the zim files in application's public directory #3979) so this popup does not make sense. Therefore, we are removing this.
• Removed all the code from the project related to this popup.
• Refactored the test cases, and removed the unnecessary test cases.
• Updated the message showing on the help screen, to inform users that direct scanning will not work in PS variant, but they can load their zim files via file picker in the application.
  

[kelson42]

@MohitMaliFtechiz Can younplease rebase?

[MohitMaliFtechiz]

@MohitMaliFtechiz Can younplease rebase?

@kelson42 Sure.

We have this same message in our help screen, should we remove this from there also? IMO we should improve this message to tell about the restriction(That directly scanning will not work due to Play Store restriction, but you can load your existing zim files via file picker).

[kelson42]

@MohitMaliFtechiz Can younplease rebase?

@kelson42 Sure.

We have this same message in our help screen, should we remove this from there also? IMO we should improve this message to tell about the restriction(That directly scanning will not work due to Play Store restriction, but you can load your existing zim files via file picker).

yes please