Simplify PermissionsSummaryHelper

Remove unused permissionCount, grantedStandardCount &
onAppWithPermissionsCountsResult.

And also no need to pass standardGrantedPermissionCount through
onPermissionSummaryResult(), because its value always equals to
grantedGroupLabels.size

Bug: 236346018
Test: m Settings
Test: m CarSettings
Change-Id: Idb8faae47b1583cc02956a97097569aa00cd17d1