Update primary index when moving package (microsoft#5204)

Fixes microsoft#5202 

## Change
When moving the primary package to a new location, update the index so
any future attempts to reference it target the correct location.

Author: JohnMcPMS

src/AppInstallerRepositoryCore/CompositeSource.cpp

@@ -1299,6 +1299,7 @@ namespace AppInstaller::Repository
                             {
                                 currentMatch.Package = std::move(Matches[latestPrimaryAvailable->PrimaryPackageIndex.value()].Package);
                                 Matches[latestPrimaryAvailable->PrimaryPackageIndex.value()].Package.reset();
+                                latestPrimaryAvailable->PrimaryPackageIndex = i;
                             }
                             continue;
                         }