Committing changes required to have SignalR depend on the centralized Microsoft BOM file for Java libraries (#3114)

clients/java/signalr/build.gradle

@@ -25,15 +25,22 @@ sourceCompatibility = 1.8
 
 repositories {
     mavenCentral()
+    // add sonatype repository (temporary, due to java-8-parent being a snapshot)
+    maven {
+        url 'https://oss.sonatype.org/content/repositories/snapshots/'
+    }
 }
 
 dependencies {
-    testImplementation 'org.junit.jupiter:junit-jupiter-api:5.3.1'
-    testCompile 'org.junit.jupiter:junit-jupiter-params:5.3.1'
-    testRuntime 'org.junit.jupiter:junit-jupiter-engine:5.3.1'
-    implementation 'com.google.code.gson:gson:2.8.5'
-    implementation 'com.squareup.okhttp3:okhttp:3.11.0'
-    implementation 'io.reactivex.rxjava2:rxjava:2.2.2'
+    implementation 'com.microsoft.maven:java-8-parent:8.0.0-SNAPSHOT'
+
+    // dependency versions imported from java-8-parent POM imported above
+    testImplementation 'org.junit.jupiter:junit-jupiter-api'
+    testCompile 'org.junit.jupiter:junit-jupiter-params'
+    testRuntime 'org.junit.jupiter:junit-jupiter-engine'
+    implementation 'com.google.code.gson:gson'
+    implementation 'com.squareup.okhttp3:okhttp'
+    implementation 'io.reactivex.rxjava2:rxjava'
 }
 
 spotless {

clients/java/signalr/settings.gradle

@@ -1,3 +1,6 @@
 rootProject.name = 'signalr'
 include 'main'
 
+// This is required for Gradle 4.6+ to support importing BOMs, like we do for the Microsoft super pom.
+// See here: https://docs.gradle.org/4.6/release-notes.html?_ga=2.220409368.162752831.1539212384-1601231980.1538950297#bom-import
+enableFeaturePreview('IMPROVED_POM_SUPPORT')