Add FakeDependencyGraphsService to replace reflection in tests

Replace hacky reflection code in DefaultAndroidUnitTestDataExtractorTest
with a proper FakeDependencyGraphsService class that extends
DefaultDependencyGraphsService and accepts DependencyGraphs in constructor.

Author: arunkumar9t2

grazel-gradle-plugin/src/test/kotlin/com/grab/grazel/fake/FakeDependencyGraphsService.kt

@@ -0,0 +1,41 @@
+/*
+ * Copyright 2022 Grabtaxi Holdings PTE LTD (GRAB)
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.grab.grazel.fake
+
+import com.grab.grazel.gradle.dependencies.DefaultDependencyGraphsService
+import com.grab.grazel.gradle.dependencies.DependencyGraphs
+import com.grab.grazel.gradle.dependencies.DependencyGraphsService
+
+/**
+ * A test fake for [DependencyGraphsService] that returns pre-configured [DependencyGraphs].
+ *
+ * Usage:
+ * ```kotlin
+ * val fakeService = FakeDependencyGraphsService(FakeDependencyGraphs())
+ * val provider = project.provider { fakeService }
+ * ```
+ */
+internal class FakeDependencyGraphsService(
+    private val dependencyGraphs: DependencyGraphs = FakeDependencyGraphs()
+) : DefaultDependencyGraphsService() {
+
+    override fun get(): DependencyGraphs = dependencyGraphs
+
+    override fun getParameters(): DependencyGraphsService.Params {
+        throw UnsupportedOperationException("Not needed for tests")
+    }
+}

grazel-gradle-plugin/src/test/kotlin/com/grab/grazel/migrate/android/DefaultAndroidUnitTestDataExtractorTest.kt

@@ -22,6 +22,7 @@ import com.grab.grazel.GrazelExtension
 import com.grab.grazel.GrazelPluginTest
 import com.grab.grazel.buildProject
 import com.grab.grazel.fake.FakeDependencyGraphs
+import com.grab.grazel.fake.FakeDependencyGraphsService
 import com.grab.grazel.gradle.ANDROID_LIBRARY_PLUGIN
 import com.grab.grazel.gradle.DefaultConfigurationDataSource
 import com.grab.grazel.gradle.KOTLIN_ANDROID_PLUGIN
@@ -113,20 +114,7 @@ class DefaultAndroidUnitTestDataExtractorTest : GrazelPluginTest() {
         val dependencyGraphs = FakeDependencyGraphs()
         val androidManifestParser: AndroidManifestParser = DefaultAndroidManifestParser()
 
-        // Create a test implementation of DependencyGraphsService
-        val testDependencyGraphsService = object : DefaultDependencyGraphsService() {
-            init {
-                // Pre-initialize with fake dependency graphs for testing
-                val field =
-                    DefaultDependencyGraphsService::class.java.getDeclaredField("dependencyGraphs")
-                field.isAccessible = true
-                field.set(this, dependencyGraphs)
-            }
-
-            override fun getParameters(): com.grab.grazel.gradle.dependencies.DependencyGraphsService.Params {
-                throw UnsupportedOperationException("Not needed for tests")
-            }
-        }
+        val testDependencyGraphsService = FakeDependencyGraphsService(dependencyGraphs)
 
         val mockDependencyGraphsService: GradleProvider<DefaultDependencyGraphsService> =
             rootProject.provider { testDependencyGraphsService }