fix: update Jackson BOM to 2.20.2 and fix logstash expected YAML

Signed-off-by: Siqi Ding <dingdd@amazon.com>

Author: Davidding4718

build.gradle

@@ -76,7 +76,7 @@ subprojects {
         }
     }
     dependencies {
-        implementation platform('com.fasterxml.jackson:jackson-bom:2.17.2')
+        implementation platform('com.fasterxml.jackson:jackson-bom:2.20.2')
         implementation platform('org.eclipse.jetty:jetty-bom:9.4.53.v20231009')
         implementation platform('io.micrometer:micrometer-bom:1.10.5')
         implementation libs.guava.core

data-prepper-api/src/test/resources/org/opensearch/dataprepper/model/configuration/sample_pipelines/sample_pipeline_plugin_empty_string.yaml

@@ -1,9 +1,9 @@
 test-pipeline:
   source:
-    stdin: ""
+    stdin: null
   processor:
-  - uppercase_string: null
+  - uppercase_string: ''
   sink:
-  - stdout: null
+  - stdout: ""
   workers: 1
   delay: 100

data-prepper-logstash-configuration/src/test/resources/org/opensearch/dataprepper/logstash/log-ingest-to-opensearch.expected.yaml

@@ -12,7 +12,7 @@ logstash-converted-pipeline:
         match:
           log:
             - "%{COMBINEDAPACHELOG}"
-    - drop_events: null
+    - drop_events: {}
     - key_value:
         source: "message"
         destination: "test"

data-prepper-plugins/event-json-codecs/build.gradle

@@ -13,8 +13,8 @@ dependencies {
     implementation 'com.fasterxml.jackson.core:jackson-databind'
     implementation 'com.fasterxml.jackson.dataformat:jackson-dataformat-ion'
     implementation 'com.fasterxml.jackson.dataformat:jackson-dataformat-xml'
-    implementation 'com.fasterxml.jackson.datatype:jackson-datatype-jsr310:2.17.0'
-    testImplementation 'com.fasterxml.jackson.datatype:jackson-datatype-jsr310:2.17.0'
+    implementation 'com.fasterxml.jackson.datatype:jackson-datatype-jsr310'
+    testImplementation 'com.fasterxml.jackson.datatype:jackson-datatype-jsr310'
     implementation libs.parquet.common
     testImplementation project(':data-prepper-test:test-common')
 }