suppress unused property for gradle.properties file

[nise-nabe]

Motivation

Gradle could set build enviromnent properties using gradle.properties.

https://docs.gradle.org/7.4.2/userguide/build_environment.html#sec:gradle_configuration_properties

the properties is used by gradle, but the properties mark as unused.

Changes

Fix not to warn unused properties. using ImplicitPropertyUsageProvider extension point.

ASIS

TOBE