[hotfix][metrics] Rename constant IS_BACKPRESSURE to IS_BACK_PRESSURE

flink-runtime/src/main/java/org/apache/flink/runtime/metrics/MetricNames.java

@@ -57,7 +57,7 @@ public class MetricNames {
     public static final String MEMORY_COMMITTED = "Committed";
     public static final String MEMORY_MAX = "Max";
 
-    public static final String IS_BACKPRESSURED = "isBackPressured";
+    public static final String IS_BACK_PRESSURED = "isBackPressured";
 
     public static final String CHECKPOINT_ALIGNMENT_TIME = "checkpointAlignmentTime";
     public static final String CHECKPOINT_START_DELAY_TIME = "checkpointStartDelayNanos";

flink-runtime/src/main/java/org/apache/flink/runtime/taskexecutor/TaskExecutor.java

@@ -696,7 +696,7 @@ public class TaskExecutor extends RpcEndpoint implements TaskExecutorGateway {
                             partitionStateChecker,
                             getRpcService().getExecutor());
 
-            taskMetricGroup.gauge(MetricNames.IS_BACKPRESSURED, task::isBackPressured);
+            taskMetricGroup.gauge(MetricNames.IS_BACK_PRESSURED, task::isBackPressured);
 
             log.info(
                     "Received task {} ({}), deploy into slot with allocation id {}.",