Fix build failure: add explicit String type to suffix parameter

The build was failing because the Gradle Kotlin DSL couldn't infer
the type of the 'suffix' parameter in the lambda, causing
'isNotBlank()' method to be unresolved.

Fixed by explicitly typing the lambda parameter as String:
`{ suffix: String -> ... }` instead of `{ suffix -> ... }`

Co-authored-by: fankes <37344460+fankes@users.noreply.github.com>

demo-app/build.gradle.kts

@@ -59,7 +59,7 @@ androidComponents {
             // Workaround for GitHub Actions.
             // Strongly transfer type to [String].
             @Suppress("UNNECESSARY_SAFE_CALL")
-            val currentSuffix = gropify.github.ci.commit.id?.let { suffix ->
+            val currentSuffix = gropify.github.ci.commit.id?.let { suffix: String ->
                 if (suffix.isNotBlank()) "-$suffix" else ""
             }
             val currentVersion = "${output.versionName.get()}$currentSuffix(${output.versionCode.get()})"