[Build] Move JUnit dependencies into the version catalog

The `kotlin-test` dependencies are left untouched as changing them affects publications, thus these versions are independent from the used inside our build
#KTI-1349 In Progress

plugins/android-extensions/android-extensions-compiler/build.gradle.kts

@@ -37,7 +37,7 @@ dependencies {
     testApi(project(":kotlin-android-extensions-runtime"))
     testApi(projectTests(":compiler:tests-common"))
     testApi(project(":kotlin-test:kotlin-test-jvm"))
-    testApi(commonDependency("junit:junit"))
+    testApi(libs.junit4)
 
     robolectricDependency("org.robolectric:android-all:5.0.2_r3-robolectric-r0")