feat: Allows additional settings to be included on settings.gradle

[beroso]

Motivation and Context

I'm integrating a flutter module inside a ionic cordova app. So accordingly to the flutter guide I need to put the following config on settings.gradle:

setBinding(new Binding([gradle: this]))
def filePath = settingsDir.parentFile.toString() + "/flutter_module/.android/include_flutter.groovy"
apply from: filePath 

But the file is regenerated on each build, and my changes are lost.

Description

Sometimes we need some extra settings on settings.gradle file, but the file is regenerated on each build.
The proposed solution applies a settings-additional.gradle file (if it exists) to the settings.gradle.

Testing

Checklist

• I've run the tests to see all new and existing tests pass
• I added automated test coverage as appropriate for this change
• Commit is prefixed with (platform) if this change only applies to one platform (e.g. (android))
• If this Pull Request resolves an issue, I linked to the issue in the text above (and used the correct keyword to close issues using keywords)
• I've updated the documentation if necessary

[codecov-commenter]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 72.12%. Comparing base (484c60e) to head (ef28380).
⚠️ Report is 11 commits behind head on master.

Additional details and impacted files

@@           Coverage Diff           @@
##           master    #1819   +/-   ##
=======================================
  Coverage   72.12%   72.12%           
=======================================
  Files          23       23           
  Lines        1844     1844           
=======================================
  Hits         1330     1330           
  Misses        514      514           

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[breautek]

I think this is a good clean enhancement and I think there isn't a risk of a breaking change. Because we have the same concept for build-extras.gradle, I don't think there is any issue doing the same for settings. Considering that Apache just made a release not that long ago, it might be some time before a feature release is made however.

A workaround that should work in the meantime if you don't want to use a custom version of cordova-android is the after prepare hook. It should allow you to manipulate the settings.gradle after Cordova has generated the file.

[erisu]

LGTM

Could you add a note to the PR description explaining how someone can add their settings-extras.gradle file to the correct directory? I suspect it will involve the <resource-file> element in config.xml.