Use complete api-versions.xml for module-lib and system-server

Previously, the check-flagged-apis.sh script used `api-versions.xml`
for `module-lib` and `system-server` which did not include the
latest up-to-date information about updatable modules or historical
information about sdk extensions which lead to false positives for
APIs from those updatable modules. This changes switches to use the
`api-versions.xml` produced by the new `api_versions_*_complete`
modules which does include that information.

Bug: 337836752
Test: Run script before and after applying this change to make sure
      that flagged APIs from updatable modules are no longer
      reported as missing.
Change-Id: If09e89a4595a19d9f00390fb5fbd24330ec11be5