* fix for some install generation issues around ly_enable_gems
* setting the right SettingsRegistry path for imported targets
* missing "include" in the exported target
* Fixed issue with the GEM_FILE argument being specified in replicated ly_enable_gems call
If the original call to `ly_enable_gems` supplied an argument for GEM_FILE, then in the replicated `ly_enable_gems` call in the install layout CMakeLists.txt, supplied both the GEMS and GEM_FILE argument which are mutually exclusive, due to the `ly_enable_gems` function populating the `ly_enable_gems_GEMS` variable from the content of the `ly_enable_gems_GEM_FILE` file.
Furthermore the install layout does not copy over the file that was parsed by the GEM_FILE argument, so it would point to a non-existent file the install layout.
* Fixed comment
Co-authored-by: lumberyard-employee-dm <56135373+lumberyard-employee-dm@users.noreply.github.com>
Esteban Papp
7d891edb9a