[ci] XA.PublishAllLogs publishes all build logs to build artifacts (dotnet#8189)

Context: dotnet@f59a3c2

By default, we only store the CI build logs of jobs that fail.
However, there are times when we would like to see the build logs for
successful jobs.

Add the ability to specify that a CI run should publish *all* of its
build logs.

When running a job from the UI, set the `XA.PublishAllLogs` variable
to `true`:

![image](https://github.com/xamarin/xamarin-android/assets/179295/928069b9-edca-449f-97cb-899f254df102)

Author: jpobst

build-tools/automation/yaml-templates/upload-results.yaml

@@ -3,7 +3,7 @@ parameters:
   configuration: $(XA.Build.Configuration)
   artifactName: results
   includeBuildResults: false
-  condition: ne(variables['Agent.JobStatus'], 'Succeeded')
+  condition: or(ne(variables['Agent.JobStatus'], 'Succeeded'), eq(variables['XA.PublishAllLogs'], 'true'))
 
 steps:
 - template: run-xaprepare.yaml