Use system API to get network location provider

The PermissionController app wil become a mainline app. Hence it cannot
use internal APIs anymore.

Hence use the newly added LocationManager system-api to get the location
provider. This forces to pass through the context everywhere.

Test: Built
Bug: 110953302
Change-Id: Id7685198da08d3e888169a6d6e8f09b0d909dff9