Plugin ignores custom file found in root directory

I created a custom file named _service.properties_ at the root of my project and I stored my google api key in it as such: `key_name="value"`
In my module's _build.gradle_ file I have this configuration:
`secrets {
propertiesFileName 'service.properties'
}`
When I run the project I get the error message saying telling me to check if the api key exist. It does already exists as I originally set my key in the _strings.xml_ file and I read directly from there, before attempting this plugin
I am using v1.3.0 of the plugin