Change metric type of LocalCacheState from counter to gauge

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

Change metric type of LocalCacheState from counter to gauge.

### Why are the changes needed?

The type of LocalCacheState metric is not reasonable since the value of this metric is a enum type not an increasable value

### Does this PR introduce any user facing changes?

No

			pr-link: #18070
			change-id: cid-61037d3580e2f25f782e1c876ced0ecad5b312a4

dora/core/client/fs/src/main/java/alluxio/client/file/cache/LocalCacheManager.java

@@ -175,9 +175,8 @@ public static LocalCacheManager create(CacheManagerOptions options,
     } else {
       mTtlEnforcerExecutor = Optional.empty();
     }
-    Metrics.registerGauges(mCacheSize, mPageMetaStore);
+    Metrics.registerGauges(mCacheSize, mPageMetaStore, mState);
     mState.set(READ_ONLY);
-    Metrics.STATE.inc();
   }
 
   @Override
@@ -751,14 +750,12 @@ private void restoreOrInit(List<PageStoreDir> pageStoreDirs) throws IOException
         } catch (IOException e) {
           LOG.error("Cache is in NOT_IN_USE.");
           mState.set(NOT_IN_USE);
-          Metrics.STATE.dec();
           throw e;
         }
       }
     }
     LOG.info("Cache is in READ_WRITE.");
     mState.set(READ_WRITE);
-    Metrics.STATE.inc();
   }
 
   private boolean restore(PageStoreDir pageStoreDir) {
@@ -1055,19 +1052,18 @@ private static final class Metrics {
      */
     private static final Counter PUT_STORE_WRITE_NO_SPACE_ERRORS =
         MetricsSystem.counter(MetricKey.CLIENT_CACHE_PUT_STORE_WRITE_NO_SPACE_ERRORS.getName());
-    /**
-     * State of the cache.
-     */
-    private static final Counter STATE =
-        MetricsSystem.counter(MetricKey.CLIENT_CACHE_STATE.getName());
 
-    private static void registerGauges(long cacheSize, PageMetaStore pageMetaStore) {
+    private static void registerGauges(long cacheSize, PageMetaStore pageMetaStore,
+        AtomicReference<State> state) {
       MetricsSystem.registerGaugeIfAbsent(
           MetricsSystem.getMetricName(MetricKey.CLIENT_CACHE_SPACE_AVAILABLE.getName()),
           () -> cacheSize - pageMetaStore.bytes());
       MetricsSystem.registerGaugeIfAbsent(
           MetricsSystem.getMetricName(MetricKey.CLIENT_CACHE_SPACE_USED.getName()),
           pageMetaStore::bytes);
+      MetricsSystem.registerGaugeIfAbsent(
+          MetricsSystem.getMetricName(MetricKey.CLIENT_CACHE_STATE.getName()),
+          () -> state.get().getValue());
     }
   }
 }

dora/core/common/src/main/java/alluxio/metrics/MetricKey.java

@@ -2531,7 +2531,7 @@ public static String getSyncMetricName(long mountId) {
   public static final MetricKey CLIENT_CACHE_STATE =
       new Builder("Client.CacheState")
           .setDescription("State of the cache: 0 (NOT_IN_USE), 1 (READ_ONLY) and 2 (READ_WRITE)")
-          .setMetricType(MetricType.COUNTER)
+          .setMetricType(MetricType.GAUGE)
           .setIsClusterAggregated(false)
           .build();
   public static final MetricKey CLIENT_META_DATA_CACHE_SIZE =