support \n on appsetting for multiline

[michelcedric]

Task name: AzureWebAppContainerV1

Description: support \n caracter for multiline
As some other Task (example : AzureFunctionAppV1) use appsettings parameter : Add multiline support.
I suggest to use \n as space (mandatory). It's better for readibility. A space is not visible and easy to forget it.
It's also more consistent with other tasks.

Documentation changes required: (N) => not required but maybe interesting to add information about this possibility

Added unit tests: (N)

Attached related issue: (N)

Checklist:

• [ OK] Task version was bumped - please check instruction how to do it
• [ OK] Checked that applied changes work as expected

Result

steps:
- task: AzureWebAppContainer@1
  displayName: 'Azure Web App on Container Deploy: test'
  inputs:
    azureSubscription: resourcegroup
    appName: test
    appSettings:  
      -input1 val1 \n
      -input2  val2 \n

[michelcedric]

@dotnet-policy-service agree

[v-mohithgc]

Hi @michelcedric , thanks for contributing.

We are currently checking these changes, since the task version here is outdated, I will create a new PR with similar changes and build it.
I will update the PR link here once its ready.

[michelcedric]

@v-mohithgc I created a new one ;)
#19022