Make appResourcesChanged check to be executed per platform

[Fatme]

In case when when something is changed in app/App_Resources/iOS folder, tns run android command executes full application build. Actually there is no need to rebuild the application in this case. Make the appResourcesDirectoryChanged to be checked per platform so no rebuild is triggered.

PR Checklist

• The PR title follows our guidelines: https://github.com/NativeScript/NativeScript/blob/master/CONTRIBUTING.md#commit-messages.
• There is an issue for the bug/feature this PR is for. To avoid wasting your time, it's best to open a suggestion issue first and wait for approval before working on it.
• You have signed the CLA.
• All existing tests are passing: https://github.com/NativeScript/nativescript-cli/blob/master/CONTRIBUTING.md#contribute-to-the-code-base
• Tests for the changes are included.

[Fatme]

run ci