Revert "Update grpc version from 1.20.0 to 1.40.0 (Azure#450)"

This reverts commit b9c9894.

Author: shreyas-gopalakrishna

lib_worker_1.6.2/grpc-netty-1.20.0.jar

@@ -76,47 +76,17 @@
 		<dependency>
 			<groupId>io.grpc</groupId>
 			<artifactId>grpc-protobuf</artifactId>
-			<version>1.40.0</version>
+			<version>1.20.0</version>
 		</dependency>
 		<dependency>
 			<groupId>io.grpc</groupId>
 			<artifactId>grpc-stub</artifactId>
-			<version>1.40.0</version>
+			<version>1.20.0</version>
 		</dependency>
 		<dependency>
 			<groupId>io.grpc</groupId>
 			<artifactId>grpc-netty</artifactId>
-			<version>1.40.0</version>
-		</dependency>
-		<dependency>
-			<groupId>io.netty</groupId>
-			<artifactId>netty-codec</artifactId>
-			<version>4.1.61.Final</version>
-		</dependency>
-		<dependency>
-			<groupId>io.netty</groupId>
-			<artifactId>netty-codec-http2</artifactId>
-			<version>4.1.61.Final</version>
-		</dependency>
-		<dependency>
-			<groupId>io.netty</groupId>
-			<artifactId>netty-transport</artifactId>
-			<version>4.1.61.Final</version>
-		</dependency>
-		<dependency>
-			<groupId>io.netty</groupId>
-			<artifactId>netty-handler</artifactId>
-			<version>4.1.61.Final</version>
-		</dependency>
-		<dependency>
-			<groupId>io.netty</groupId>
-			<artifactId>netty-codec-http</artifactId>
-			<version>4.1.61.Final</version>
-		</dependency>
-		<dependency>
-			<groupId>io.netty</groupId>
-			<artifactId>netty-handler-proxy</artifactId>
-			<version>4.1.61.Final</version>
+			<version>1.20.0</version>
 		</dependency>
 		<dependency>
 			<groupId>org.apache.commons</groupId>
@@ -149,11 +119,6 @@
 			<version>1.49</version>
 			<scope>test</scope>
 		</dependency>
-		<dependency>
-			<groupId>com.google.code.gson</groupId>
-			<artifactId>gson</artifactId>
-			<version>2.8.5</version>
-		</dependency>
 	</dependencies>
 
 	<build>

lib_worker_1.6.2/grpc-netty-1.40.0.jar

@@ -22,7 +22,7 @@
 public class JavaWorkerClient implements AutoCloseable {
     public JavaWorkerClient(IApplication app) {
         WorkerLogManager.initialize(this, app.logToConsole());
-        ManagedChannelBuilder<?> chanBuilder = ManagedChannelBuilder.forAddress(app.getHost(), app.getPort()).usePlaintext();
+        ManagedChannelBuilder<?> chanBuilder = ManagedChannelBuilder.forAddress(app.getHost(), app.getPort()).usePlaintext(true);
         chanBuilder.maxInboundMessageSize(Integer.MAX_VALUE);
 
         this.channel = chanBuilder.build();