Replace the 'answer' PendingIntent in ringing call notifications

[jmartinesp]

Type of change

• Feature
• Bugfix
• Technical
• Other :

Content

Added the CANCEL_CURRENT flag to the pending intent so it's replaced.

Motivation and context

Fixes #3085.

Tests

• Receive a ringing call from another user. Ignore or decline it.
• Receive a new one from a different user, answer it.

The call you join should be the 2nd one, not the first one.

Tested devices

• Physical
• Emulator
• OS version(s): 14

Checklist

• Changes have been tested on an Android device or Android emulator with API 23
• UI change has been tested on both light and dark themes
• Accessibility has been taken into account. See https://github.com/element-hq/element-x-android/blob/develop/CONTRIBUTING.md#accessibility
• Pull request is based on the develop branch
• Pull request includes a new file under ./changelog.d. See https://github.com/element-hq/element-x-android/blob/develop/CONTRIBUTING.md#changelog
• Pull request includes screenshots or videos if containing UI changes
• Pull request includes a sign off
• You've made a self review of your PR

[github-actions]

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[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 75.98%. Comparing base (ec06ce4) to head (abf1152).
Report is 6 commits behind head on develop.

Additional details and impacted files

@@           Coverage Diff            @@
##           develop    #3093   +/-   ##
========================================
  Coverage    75.98%   75.98%           
========================================
  Files         1634     1634           
  Lines        38596    38596           
  Branches      7461     7461           
========================================
  Hits         29326    29326           
  Misses        5380     5380           
  Partials      3890     3890           

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[bmarty]

OK, just a question about the impact for the user.

[sonarcloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarCloud

[toger5]

Super nice to have this fixes so quickly.