chore(testkit): prepare for testkit-plugin release 0.17.

Author: autonomousapps

testkit/gradle-testkit-plugin/CHANGELOG.md

@@ -1,5 +1,8 @@
 Gradle TestKit Plugin Changelog
 
+# Version 0.17
+* [Feat] Update default support lib version to 0.21.
+
 # Version 0.16
 * [Fix] set apiVersion and languageVersion to 2.0 for Gradle 8.11 support.
 

testkit/gradle-testkit-plugin/build.gradle.kts

@@ -5,7 +5,7 @@ plugins {
   id("com.github.gmazzo.buildconfig")
 }
 
-version = "0.17-SNAPSHOT"
+version = "0.17"
 val isSnapshot: Boolean = version.toString().endsWith("SNAPSHOT")
 val isRelease: Boolean = !isSnapshot
 

testkit/gradle-testkit-plugin/src/main/kotlin/com/autonomousapps/GradleTestKitSupportExtension.kt

@@ -261,7 +261,7 @@ public abstract class GradleTestKitSupportExtension(private val project: Project
   internal companion object {
 
     // TODO(tsr): can we inject these values so they're not hardcoded?
-    private const val DEFAULT_SUPPORT_VERSION = "0.20"
+    private const val DEFAULT_SUPPORT_VERSION = "0.21"
     private const val DEFAULT_TRUTH_VERSION = "1.6.1"
 
     fun create(project: Project): GradleTestKitSupportExtension {