Fix boolean parsing warning when reading configuration

Compiling the plugin raises a warning:

```
[removal] Boolean(String) in Boolean has been deprecated and marked for removal
```

Fix by calling  `parseBoolean` instead [1]

[1] https://docs.oracle.com/javase%2F9%2Fdocs%2Fapi%2F%2F/java/lang/Boolean.html#Boolean-java.lang.String-

Change-Id: I4da5f55db10b18f956301df620d5822e31585954
diff --git a/src/main/java/com/googlesource/gerrit/plugins/kinesis/Configuration.java b/src/main/java/com/googlesource/gerrit/plugins/kinesis/Configuration.java
index 64fbecd..fc76b19 100644
--- a/src/main/java/com/googlesource/gerrit/plugins/kinesis/Configuration.java
+++ b/src/main/java/com/googlesource/gerrit/plugins/kinesis/Configuration.java
@@ -92,7 +92,7 @@
         getStringParam(pluginConfig, STREAM_EVENTS_TOPIC_FIELD, DEFAULT_STREAM_EVENTS_TOPIC);
     this.sendStreamEvents =
         Optional.ofNullable(getStringParam(pluginConfig, SEND_STREAM_EVENTS_FIELD, null))
-            .map(Boolean::new)
+            .map(Boolean::parseBoolean)
             .orElse(DEFAULT_SEND_STREAM_EVENTS);
     this.numberOfSubscribers =
         Integer.parseInt(
@@ -153,7 +153,7 @@
 
     this.sendAsync =
         Optional.ofNullable(getStringParam(pluginConfig, SEND_ASYNC_FIELD, null))
-            .map(Boolean::new)
+            .map(Boolean::parseBoolean)
             .orElse(DEFAULT_SEND_ASYNC);
 
     this.awsConfigurationProfileName =