ContentProvider: Use the mode the use chosen from the dialog

When the user try to delete contacts, we will show a dialog
to let the user decide whether the app can do the delete
operation or not. This issue's root cuase is that we did not
return the result we get from the user's choice.

Return the mode user has selected instead of the default mode
when we are checking the app's permission.

CRs-Fixed: 750841

Change-Id: I53355d6ff367fcc88330e39986d0a7fd7896861c