feat: migrate to 2.x samples and clear unused samples (#10059)

* feat: clean up unused code samples

* feat: update model name

* fix: remove test-cases for deleted files

* fix: clear unsed samples

* fix: lint error and assertion error

Author: msampathkumar

aiplatform/src/main/java/aiplatform/batchpredict/CreateBatchPredictionGeminiBigqueryJobSample.java

@@ -66,7 +66,7 @@ public static BatchPredictionJob createBatchPredictionGeminiBigqueryJobSample(
       String modelName =
           String.format(
               "projects/%s/locations/%s/publishers/google/models/%s",
-              project, location, "gemini-1.5-flash-002");
+              project, location, "gemini-2.0-flash-001");
 
       BatchPredictionJob batchPredictionJob =
           BatchPredictionJob.newBuilder()

aiplatform/src/main/java/aiplatform/batchpredict/CreateBatchPredictionGeminiJobSample.java

@@ -72,7 +72,7 @@ public static BatchPredictionJob createBatchPredictionGeminiJobSample(
       String modelName =
           String.format(
               "projects/%s/locations/%s/publishers/google/models/%s",
-              project, location, "gemini-1.5-flash-002");
+              project, location, "gemini-2.0-flash-001");
 
       BatchPredictionJob batchPredictionJob =
           BatchPredictionJob.newBuilder()