Revert "Fix as per micronaut-projects/micronaut-servlet#548"

This reverts commit ba893a5.

function-aws-api-proxy/src/main/java/io/micronaut/function/aws/proxy/ApiGatewayServletRequest.java

@@ -118,15 +118,7 @@ protected static HttpMethod parseMethod(Supplier<String> httpMethodConsumer) {
 
     @Override
     public InputStream getInputStream() throws IOException {
-        if (servletByteBuffer == null) {
-            // Read all the input stream into memory, so we can parse it multiple times (where we need different formats)
-            this.servletByteBuffer = new ByteArrayByteBuffer<>(getBodyBytes());
-        }
-        if (parsedBody != null) {
-            // We have already parsed a body, this is a second call to getInputStream probably for a different type, so reset the reader.
-            this.servletByteBuffer.readerIndex(0);
-        }
-        return servletByteBuffer.toInputStream();
+        return servletByteBuffer != null ? servletByteBuffer.toInputStream() : new ByteArrayInputStream(getBodyBytes());
     }
 
     @Override