RUM-8673 Update UserInfo API to make id mandatory.

[maciejburda]

What does this PR do?

Makes id parameter of setUserInfo() mandatory. Old signature is kept with deprecation warning.

Motivation

Change requested by PA.

Review checklist (to be filled by reviewers)

• Feature or bugfix MUST have appropriate tests (unit, integration, e2e)
• 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)

[codecov-commenter]

Codecov Report

Attention: Patch coverage is 20.00000% with 4 lines in your changes missing coverage. Please review.

Project coverage is 70.06%. Comparing base (fe2a4ca) to head (1370ab5).

Files with missing lines	Patch %	Lines
...ore/src/main/kotlin/com/datadog/android/Datadog.kt	20.00%	4 Missing ⚠️

Additional details and impacted files

@@             Coverage Diff             @@
##           develop    #2509      +/-   ##
===========================================
+ Coverage    70.00%   70.06%   +0.06%     
===========================================
  Files          794      794              
  Lines        29873    29879       +6     
  Branches      4994     4990       -4     
===========================================
+ Hits         20911    20932      +21     
+ Misses        7582     7572      -10     
+ Partials      1380     1375       -5     

Files with missing lines	Coverage Δ
...ore/src/main/kotlin/com/datadog/android/Datadog.kt	71.43% <20.00%> (-4.82%)	⬇️

... and 28 files with indirect coverage changes