Replace generated code with source .proto files

This change replaces the generated Messages.java file with the source .proto files.
It also includes the pom.xml changes needed to install protoc from Maven Central, and use it to compile the wrapper java code.

amazon-kinesis-client/pom.xml

@@ -180,6 +180,13 @@
  </developers>
 
  <build>
+ <extensions>
+ <extension>
+ <groupId>kr.motd.maven</groupId>
+ <artifactId>os-maven-plugin</artifactId>
+ <version>1.6.0</version>
+ </extension>
+ </extensions>
  <pluginManagement>
  <plugins>
  <plugin>
@@ -195,6 +202,21 @@
  </pluginManagement>
 
  <plugins>
+ <plugin>
+ <groupId>org.xolstice.maven.plugins</groupId>
+ <artifactId>protobuf-maven-plugin</artifactId>
+ <version>0.6.1</version>
+ <executions>
+ <execution>
+ <goals>
+ <goal>compile</goal>
+ </goals>
+ </execution>
+ </executions>
+ <configuration>
+ <protocArtifact>com.google.protobuf:protoc:3.21.0:exe:${os.detected.classifier}</protocArtifact>
+ </configuration>
+ </plugin>
  <plugin>
  <groupId>org.apache.maven.plugins</groupId>
  <artifactId>maven-surefire-plugin</artifactId>