driver/java: pass task network isolation to executor

Without passing the network isolation configuration to the executor,
java tasks are not placed in the same network namespace as the other
processes in their task group, which breaks Consul Connect.

drivers/java/driver.go

@@ -344,17 +344,18 @@ func (d *Driver) StartTask(cfg *drivers.TaskConfig) (*drivers.TaskHandle, *drive
 	}
 
 	execCmd := &executor.ExecCommand{
-		Cmd:            absPath,
-		Args:           args,
-		Env:            cfg.EnvList(),
-		User:           user,
-		ResourceLimits: true,
-		Resources:      cfg.Resources,
-		TaskDir:        cfg.TaskDir().Dir,
-		StdoutPath:     cfg.StdoutPath,
-		StderrPath:     cfg.StderrPath,
-		Mounts:         cfg.Mounts,
-		Devices:        cfg.Devices,
+		Cmd:              absPath,
+		Args:             args,
+		Env:              cfg.EnvList(),
+		User:             user,
+		ResourceLimits:   true,
+		Resources:        cfg.Resources,
+		TaskDir:          cfg.TaskDir().Dir,
+		StdoutPath:       cfg.StdoutPath,
+		StderrPath:       cfg.StderrPath,
+		Mounts:           cfg.Mounts,
+		Devices:          cfg.Devices,
+		NetworkIsolation: cfg.NetworkIsolation,
 	}
 
 	ps, err := exec.Launch(execCmd)