1) create merged wheels.inc file(s) as part of build-pkgs.
These files can be published by CENGN layer builds, and
be referenced by the 'container' layer build.
2) get-stx-wheels.sh needs to find wheels.inc files from
lower layer builds. The will be fould under
${MY_REPO}/cgcs-centos-repo/layer_wheels_inc.
3) build-helm-charts.sh must now also search for helm
rpms under ${MY_REPO}/cgcs-centos-repo/Binary/noarch
for chart packages built by lower layers.
Story: 2006166
Task: 38979
Depends-On: https://review.opendev.org/711773
Depends-On: https://review.opendev.org/711774
Change-Id: I91650d3e1746a45c8ac118cca58e9b64f30c5b72
Signed-off-by: Scott Little <scott.little@windriver.com>