Fix Android unit test tasks not running in allTests

The Android unit test tasks were not created by the Kotlin Gradle
plugin, so the plugin didn't add the
tadk dependencies to its aggregating
`allTests` task.

Issue #KT-38456
Issue #KT-44227

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

@@ -457,6 +457,15 @@ open class KotlinAndroid36GradleIT : KotlinAndroid34GradleIT() {
             }
         }
     }
+
+    @Test
+    fun `test MPP allTests task depending on Android unit tests`(): Unit = with(Project("new-mpp-android")) {
+        build(":lib:allTests", "--dry-run") {
+            assertSuccessful()
+            assertContains(":lib:testDebugUnitTest SKIPPED")
+            assertContains(":lib:testReleaseUnitTest SKIPPED")
+        }
+    }
 }
 
 open class KotlinAndroid70GradleIT : KotlinAndroid36GradleIT() {

libraries/tools/kotlin-gradle-plugin/src/main/kotlin/org/jetbrains/kotlin/gradle/plugin/KotlinPlugin.kt

@@ -7,12 +7,9 @@ package org.jetbrains.kotlin.gradle.plugin
 
 import com.android.build.gradle.*
 import com.android.build.gradle.BasePlugin
-import com.android.build.gradle.api.AndroidSourceSet
+import com.android.build.gradle.api.*
-import com.android.build.gradle.api.BaseVariant
-import com.android.build.gradle.api.SourceKind
 import org.gradle.api.*
 import org.gradle.api.artifacts.repositories.ArtifactRepository
-import org.gradle.api.attributes.Bundling
 import org.gradle.api.attributes.Category
 import org.gradle.api.attributes.Usage
 import org.gradle.api.file.ConfigurableFileTree
@@ -47,6 +44,7 @@ import org.jetbrains.kotlin.gradle.targets.js.jsPluginDeprecationMessage
 import org.jetbrains.kotlin.gradle.targets.jvm.KotlinJvmTarget
 import org.jetbrains.kotlin.gradle.tasks.*
 import org.jetbrains.kotlin.gradle.tasks.KotlinCompile
+import org.jetbrains.kotlin.gradle.testing.internal.kotlinTestRegistry
 import org.jetbrains.kotlin.gradle.tooling.includeKotlinToolingMetadataInApk
 import org.jetbrains.kotlin.gradle.utils.*
 import org.jetbrains.kotlin.utils.addToStdlib.cast
@@ -883,6 +881,8 @@ abstract class AbstractAndroidProjectHandler(private val kotlinConfigurationTool
         }
 
         project.includeKotlinToolingMetadataInApk()
+
+        addAndroidUnitTestTasksAsDependenciesToAllTest(project)
     }
 
     /**
@@ -981,6 +981,24 @@ abstract class AbstractAndroidProjectHandler(private val kotlinConfigurationTool
             kotlinOptions.jvmTarget = "1.6"
     }
 
+    private fun addAndroidUnitTestTasksAsDependenciesToAllTest(project: Project) {
+        val allTestTaskName = project.kotlinTestRegistry.allTestsTaskName
+        project.tasks.matching { it.name == allTestTaskName }.configureEach { task ->
+            task.dependsOn(project.provider {
+                val androidUnitTestTasks = mutableListOf<Any>()
+                forEachVariant(project) { variant ->
+                    if (variant is UnitTestVariant) {
+                        // There's no API for getting the Android unit test tasks from the variant, so match them by name:
+                        androidUnitTestTasks.add(project.provider {
+                            project.tasks.matching { it.name == lowerCamelCaseName("test", variant.name) }
+                        })
+                    }
+                }
+                androidUnitTestTasks
+            })
+        }
+    }
+
     private fun preprocessVariant(
         variantData: BaseVariant,
         compilation: KotlinJvmAndroidCompilation,