Use String notation for Gradle dependency declarations

In Gradle, dependencies can be expressed as a String like "groupId:artifactId:version", or equivalently as a Map like group: 'groupId', name: 'artifactId', version: 'version', or as positional parameters like ("groupId", "artifactId", "version"). This recipe replaces dependencies represented as Maps or positional parameters with an equivalent dependency represented as a String, as recommended per the Gradle best practices for dependencies to use a single GAV.