Build-Variant Specific Properties not working when file name as more then one dot.

## Config
build.gradle.kts
```kotlin
secrets {
propertiesFileName = "secrets.properties"
}
```
files names on root project :
- `debug.secrets.properties`
- `secrets.properties`

## Result Error
Always show the `secrets.properties` content, even when set as

## Solution
There is no bug, I finaly realise my mistake. But in case of someone did the same I have to say you you have to replace the first world by the build variant insted of add it.
So, for `propertiesFileName = "secrets.properties"` and a `debug` variant, use file named `debug.properties`.