Add --alignment-preserved true when signing APK for F-Droid.

[bmarty]

Content

Add parameter --alignment-preserved true when signing APK for F-Droid to ensure reproducible build is working as expected.

Second commit is improving the PR template, I am lazy to create a PR just for this.

Motivation and context

Closes #3151

Screenshots / GIFs

Tests

• NA

Tested devices

• NA

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 title will be used in the release note, it clearly define what will change for the user
• 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 76.02%. Comparing base (c550436) to head (33b8f65).

Additional details and impacted files

@@           Coverage Diff            @@
##           develop    #3161   +/-   ##
========================================
  Coverage    76.02%   76.02%           
========================================
  Files         1635     1635           
  Lines        38559    38559           
  Branches      7457     7457           
========================================
  Hits         29313    29313           
  Misses        5360     5360           
  Partials      3886     3886           

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[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