KT-27675: Following the Gradle Java plugin, enable Kapt cache by default

As the Gradle Java plugin considers Java annotation processing cacheable
with any annotation processors, we can enable build cache by default
for Kapt tasks, leaving the opt-out flag just in case.

Issue #KT-27675 Fixed

libraries/tools/kotlin-gradle-plugin-integration-tests/src/test/kotlin/org/jetbrains/kotlin/gradle/BuildCacheIT.kt

@@ -135,27 +135,12 @@ class BuildCacheIT : BaseGradleIT() {
     }
 
     @Test
-    fun testKaptCachingDisabledByDefault() = with(Project("simple", GRADLE_VERSION, directoryPrefix = "kapt2")) {
+    fun testKaptCachingEnabledByDefault() = with(Project("simple", GRADLE_VERSION, directoryPrefix = "kapt2")) {
         prepareLocalBuildCache()
 
-        build("build") {
-            assertSuccessful()
-            assertContains("Packing task ':kaptGenerateStubsKotlin'")
-            assertNotContains("Packing task ':kaptKotlin'")
-            assertContains("Caching disabled for task ':kaptKotlin': 'Caching is disabled by default for kapt")
-        }
-
-        File(projectDir, "build.gradle").appendText(
-            "\n" + """
-            afterEvaluate {
-                kaptKotlin.useBuildCache = true
-            }
-            """.trimIndent()
-        )
-
         build("clean", "build") {
             assertSuccessful()
-            assertContains(":kaptGenerateStubsKotlin FROM-CACHE")
+            assertContains("Packing task ':kaptGenerateStubsKotlin'")
             assertContains("Packing task ':kaptKotlin'")
         }
 
@@ -164,6 +149,21 @@ class BuildCacheIT : BaseGradleIT() {
             assertContains(":kaptGenerateStubsKotlin FROM-CACHE")
             assertContains(":kaptKotlin FROM-CACHE")
         }
+
+        File(projectDir, "build.gradle").appendText(
+            "\n" + """
+            afterEvaluate {
+                kaptKotlin.useBuildCache = false
+            }
+            """.trimIndent()
+        )
+
+        build("clean", "build") {
+            assertSuccessful()
+            assertContains(":kaptGenerateStubsKotlin FROM-CACHE")
+            assertNotContains(":kaptKotlin FROM-CACHE")
+            assertContains("Caching disabled for task ':kaptKotlin': 'Caching is disabled for kapt")
+        }
     }
 }