Add reflection dependency (opensearch-project#136)

Signed-off-by: Heemin Kim <[email protected]>

build.gradle

@@ -145,6 +145,12 @@ dependencies {
     compileOnly fileTree(dir: knnJarDirectory, include: '*.jar')
     api group: 'org.opensearch', name:'opensearch-ml-client', version: "${opensearch_build}"
     implementation group: 'org.apache.commons', name: 'commons-lang3', version: '3.10'
+    // ml-common excluded reflection for runtime so we need to add it by ourselves.
+    // https://github.com/opensearch-project/ml-commons/commit/464bfe34c66d7a729a00dd457f03587ea4e504d9
+    // TODO: Remove following three lines of dependencies if ml-common include them in their jar
+    runtimeOnly group: 'org.reflections', name: 'reflections', version: '0.9.12'
+    runtimeOnly group: 'org.javassist', name: 'javassist', version: '3.29.2-GA'
+    runtimeOnly group: 'org.opensearch', name: 'common-utils', version: "${opensearch_build}"
 }
 
 // In order to add the jar to the classpath, we need to unzip the