meta-agl-core: Centralize qtlocation tweaks

meta-agl-core: Centralize qtlocation tweaks

To avoid issues when combining the meta-agl-ic-container and
meta-agl-demo layers, move the meta-agl-demo qtlocation bbappend to
the pre-existing meta-qt5 dynamic-layers hierarchy in meta-agl-core.
This does have a minor side-effect of enabling more map plugins in
the QtLocation users in the meta-agl-ic-container guests, but seems
more robust overall with respect to future work on binary package
feeds.

Bug-AGL: SPEC-4703

Change-Id: I8244c7ac7a22b25d28da7b8ffbf2454b68bee591
Signed-off-by: Scott Murray <scott.murray@konsulko.com>
Reviewed-on: https://gerrit.automotivelinux.org/gerrit/c/AGL/meta-agl/+/28473
Tested-by: Jenkins Job builder account
ci-image-build: Jenkins Job builder account
ci-image-boot-test: Jenkins Job builder account
Reviewed-by: Jan-Simon Moeller <jsmoeller@linuxfoundation.org>