[SPARK-56042][SS] Fix swapped external/internal col family count metrics in RocksDBStateStoreProvider

### What changes were proposed in this pull request?

Fix swapped external/internal col family count metrics in RocksDBStateStoreProvider

### Why are the changes needed?

### Does this PR introduce _any_ user-facing change?

no

### How was this patch tested?

tests added

### Was this patch authored or co-authored using generative AI tooling?

no

Closes #54874 from jerrypeng/SPARK-56042.

Authored-by: Jerry Peng <jerry.peng@databricks.com>
Signed-off-by: Jungtaek Lim <kabhwan.opensource@gmail.com>

Author: jerrypeng

sql/core/src/main/scala/org/apache/spark/sql/execution/streaming/state/RocksDBStateStoreProvider.scala

@@ -674,8 +674,8 @@ private[sql] class RocksDBStateStoreProvider
           CUSTOM_METRIC_FLUSH_WRITTEN_BYTES -> nativeOpsMetrics("totalBytesWrittenByFlush"),
           CUSTOM_METRIC_PINNED_BLOCKS_MEM_USAGE -> rocksDBMetrics.pinnedBlocksMemUsage,
           CUSTOM_METRIC_NUM_INTERNAL_COL_FAMILIES_KEYS -> rocksDBMetrics.numInternalKeys,
-          CUSTOM_METRIC_NUM_EXTERNAL_COL_FAMILIES -> internalColFamilyCnt(),
-          CUSTOM_METRIC_NUM_INTERNAL_COL_FAMILIES -> externalColFamilyCnt(),
+          CUSTOM_METRIC_NUM_EXTERNAL_COL_FAMILIES -> externalColFamilyCnt(),
+          CUSTOM_METRIC_NUM_INTERNAL_COL_FAMILIES -> internalColFamilyCnt(),
           CUSTOM_METRIC_NUM_SNAPSHOTS_AUTO_REPAIRED -> rocksDBMetrics.numSnapshotsAutoRepaired,
           CUSTOM_METRIC_FORCE_SNAPSHOT -> (if (forceSnapshotOnCommit) 1L else 0L)
         ) ++ rocksDBMetrics.zipFileBytesUncompressed.map(bytes =>

sql/core/src/test/scala/org/apache/spark/sql/execution/streaming/state/RocksDBStateStoreSuite.scala

@@ -2178,6 +2178,15 @@ class RocksDBStateStoreSuite extends StateStoreSuiteBase[RocksDBStateStoreProvid
         val metricPair = store
           .metrics.customMetrics.find(_._1.name == "rocksdbNumInternalColFamiliesKeys")
         assert(metricPair.isDefined && metricPair.get._2 === 4)
+        // Verify external/internal column family count metrics
+        val externalColFamilyCount = store
+          .metrics.customMetrics.find(_._1.name == "rocksdbNumExternalColumnFamilies")
+        // 2 external col families: default + testColFamily
+        assert(externalColFamilyCount.isDefined && externalColFamilyCount.get._2 === 2)
+        val internalColFamilyCount = store
+          .metrics.customMetrics.find(_._1.name == "rocksdbNumInternalColumnFamilies")
+        // 1 internal col family: $testIndex
+        assert(internalColFamilyCount.isDefined && internalColFamilyCount.get._2 === 1)
         val store1 = provider.getStore(1)
         assert(rowPairsToDataSet(store1.iterator(cfName)) ===
           Set(("a", 0) -> 1, ("b", 0) -> 2, ("c", 0) -> 3, ("d", 0) -> 4, ("e", 0) -> 5))