[O11y][GCP Load balancing] Lens Migration

[rajvi-patel-22]

Manually migrate GCP Load balancing visualizations to the lens in the current Kibana version 8.7.1 itself.

Preparation of data for testing

• [x] Use sample_event.json / setup live instance using docker / mock data using a mock server to populate dashboards

Migration stats

  | Before Migration |   |   | After Migration |   |   -- | -- | -- | -- | -- | -- | --   | Lens | Vizualization | Old Control panels | Lens | Vizualization | New Input controls [Metrics GCP] Load Balancing TCP SSL Proxy Overview | 0 | 5 | 1 |  5 |0|  1 [Metrics GCP] Load Balancing L3 Overview | 0 | 4 | 1 |4   |0|  1 [Metrics GCP] Load Balancing HTTPS Overview | 0 | 6 | 1 | 6  |0|1  

Dashboard : Load Balancing TCP SSL Proxy Overview

• [x] Migrate 5 visualization to lens and 1 old controls to new input controls.
  • https://github.com/elastic/integrations/pull/7459

    Dashboard : Load Balancing L3 Proxy Overview

• [x] Migrate 4 visualization to lens and 1 old controls to new input controls.
  • https://github.com/elastic/integrations/pull/7461

    Dashboard : Load Balancing HTTPS Proxy Overview

• [x] Migrate 6 visualization to lens and 1 old controls to new input controls.
  • https://github.com/elastic/integrations/pull/7458

Verification and Validation

• [x] Verification of functionality remains the same after migration in Kibana
• [x] Verification of data count of after-migrated visualization with before-migrated visualization in Kibana
• [x] Verification of Dashboards is not distorted in the supported Kibana version (TBD)

[rajvi-patel-22]

The dashboards contain incorrect fields. Hence, lens migration task is blocked due to this issue: https://github.com/elastic/integrations/issues/7242