Set default captiveportallogin app in AOSP

Make sure the default CaptivePortalLogin application bundled in AOSP is
configured, so that it receives appropriate permissions.

This avoids potential problems where on an AOSP-based device, setting
the config was forgotten, and the default captive portal which expected
the permissions does not get them.

Bug: 228991143
Test: m; check CaptivePortalLogin has POST_NOTIFICATIONS
Change-Id: Iec7e3449d6b34ba6ff77e64b1d4bf00809629719