[RUM-10693] [FIX] React Navigation duplicate views

[marco-saia-datadog]

What does this PR do?

• Fixes duplication of first RUM View when using @datadog/mobile-react-navigation.
• Adds navigation timeline for internal debugging

Motivation

The first RUM view is always duplicated when tracking views with @datadog/mobile-react-navigation.

Reason

Calling startTrackingViews() creates a RUM View and registers a navigation state listener, which triggers for the same view, leading to two identical RUM views being created.

Before the fix

Two calls to startView() at startup -> RUM View Home is duplicated.

After the fix

The initial second call to startView() is dismissed, and the subsequent calls are not affected.

Review checklist (to be filled by reviewers)

• Feature or bugfix MUST have appropriate tests
• Make sure you discussed the feature or bugfix with the maintaining team in an Issue
• Make sure each commit and the PR mention the Issue number (cf the CONTRIBUTING doc)
• If this PR is auto-generated, please make sure also to manually update the code related to the change

[cdn34dd]

Looks good