Remove oversized truncated log validation from genai-v2 test (#618)

## Summary
- Remove the 1.2MB `logger.info("X" * 1_200_000)` from genai_service_v2
sample app — it exceeds CloudWatch OTLP endpoint's 1MB request size
limit, causing log export failures
- Remove the corresponding truncated log validation (template, enum,
validation config)

## Test plan
- [x] Ran trace validation locally — passed
- [x] Ran log validation locally — passed
- [x] Ran metric validation locally — passed

Author: wangzlei

sample-apps/python/genai_service_v2/server.py

@@ -101,8 +101,6 @@ async def chat(request):
     body = await request.json()
     message = body.get("message", "")
 
-    logger.info("X" * 1_200_000)
-
     # Emit OTel Metrics
     meter = metrics.get_meter("genai-meter", "1.0.0")
     token_counter = meter.create_histogram(

validator/src/main/java/com/amazon/aoc/fileconfigs/PredefinedExpectedTemplate.java

@@ -262,7 +262,6 @@ public enum PredefinedExpectedTemplate implements FileConfig {
   /** Python EC2 GenAI v2 (AgentCore Collector) Test Case Validations */
   PYTHON_EC2_ADOT_GENAI_V2_TRACE("/expected-data-template/python/ec2/adot-genai-v2/genai-trace.mustache"),
   PYTHON_EC2_ADOT_GENAI_V2_LLO_SPAN_ATTRIBUTE_LOG("/expected-data-template/python/ec2/adot-genai-v2/genai-log-llo-span-attribute.mustache"),
-  PYTHON_EC2_ADOT_GENAI_V2_TRUNCATED_LOG("/expected-data-template/python/ec2/adot-genai-v2/genai-log-truncated.mustache"),
   PYTHON_EC2_ADOT_GENAI_V2_METRIC("/expected-data-template/python/ec2/adot-genai-v2/genai-metric.mustache"),
 
   /** Python K8S Test Case Validations */

validator/src/main/resources/expected-data-template/python/ec2/adot-genai-v2/genai-log-truncated.mustache

@@ -5,10 +5,3 @@
   callingType: "http"
   expectedLogStructureTemplate: "PYTHON_EC2_ADOT_GENAI_V2_LLO_SPAN_ATTRIBUTE_LOG"
   cwLogFilterPattern: "{ ($.scope.name = \"openinference.instrumentation.langchain\") && ($.body.input.messages[0].content = \"*clinic hours*\") && ($.traceId = \"{{traceId}}\") }"
--
-  validationType: "cw-log"
-  httpPath: "/ai-chat"
-  httpMethod: "post"
-  callingType: "http"
-  expectedLogStructureTemplate: "PYTHON_EC2_ADOT_GENAI_V2_TRUNCATED_LOG"
-  cwLogFilterPattern: "{ ($.scope.name = \"server\") && ($.attributes.['code.function.name'] = \"chat\") && ($.traceId = \"{{traceId}}\") }"