Add new home ui test for maps

[junqiu-lei]

Description

This PR:

1. Add new home ui test for maps dashboards
2. Fix failure in add_map_to_dashboard case

Issues Resolved

opensearch-project/dashboards-maps#649
opensearch-project/dashboards-maps#663

Check List

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[junqiu-lei]

The github CI failure isn't related to this PR

The Test is verified through https://github.com/junqiu-lei/dashboards-maps/actions/runs/10638937009/job/29495905154?pr=22.

       Spec                                              Tests  Passing  Failing  Pending  Skipped  
  ┌────────────────────────────────────────────────────────────────────────────────────────────────┐
  │ ✔  plugins/custom-import-map-dashboard      01:00        1        1        -        -        - │
  │    s/0_add_saved_object.js                                                                     │
  ├────────────────────────────────────────────────────────────────────────────────────────────────┤
  │ ✔  plugins/custom-import-map-dashboard      00:59        1        1        -        -        - │
  │    s/1_import_vector_map_tab.spec.js                                                           │
  ├────────────────────────────────────────────────────────────────────────────────────────────────┤
  │ ✔  plugins/custom-import-map-dashboard      01:33        1        1        -        -        - │
  │    s/2_opensearchMapLayer.spec.js                                                              │
  ├────────────────────────────────────────────────────────────────────────────────────────────────┤
  │ ✔  plugins/custom-import-map-dashboard      01:09        1        1        -        -        - │
  │    s/3_add_saved_object.spec.js                                                                │
  ├────────────────────────────────────────────────────────────────────────────────────────────────┤
  │ ✔  plugins/custom-import-map-dashboard      02:38        2        2        -        -        - │
  │    s/4_documentsLayer.spec.js                                                                  │
  ├────────────────────────────────────────────────────────────────────────────────────────────────┤
  │ ✔  plugins/custom-import-map-dashboard      01:19        1        1        -        -        - │
  │    s/5_add_map_to_dashboard.spec.js                                                            │
  ├────────────────────────────────────────────────────────────────────────────────────────────────┤
  │ ✔  plugins/custom-import-map-dashboard      00:55        1        1        -        -        - │
  │    s/6_geojson_file_upload.spec.js                                                             │
  ├────────────────────────────────────────────────────────────────────────────────────────────────┤
  │ ✔  plugins/custom-import-map-dashboard      01:20        2        2        -        -        - │
  │    s/7_enable_new_home_ui.spec.js                                                              │
  └────────────────────────────────────────────────────────────────────────────────────────────────┘
    ✔  All specs passed!                        11:00       10       10        -        -        -  

[yujin-emma]

LGTM