Remove privapp grants for CaptivePortalLogin

CaptivePortalLogin is not a privileged app, so it cannot get these
permissions anyway.

Test: CaptivePortalLogin working without the permissions
Bug: 151214275
Change-Id: I283b8068b9eada28d92c9d550473106a1b680a27
Merged-In: I283b8068b9eada28d92c9d550473106a1b680a27
(cherry picked from commit 53839762)