[server] Remove a global disk quota metric (#860)

* remove a global disk quota metric

Author: adamxchen

clients/da-vinci-client/src/main/java/com/linkedin/davinci/stats/HostLevelIngestionStats.java

@@ -271,11 +271,6 @@ public HostLevelIngestionStats(
             "ingestion_stuck_by_memory_constraint"));
 
     // Stats which are per-store only:
-    // disk quota allowed for a store without replication. It should be as a straight line unless we bumps the disk
-    // quota
-    // allowed.
-    registerSensor(new AsyncGauge((ignored, ignored2) -> diskQuotaAllowedGauge, "global_store_disk_quota_allowed"));
-
     String keySizeSensorName = "record_key_size_in_bytes";
     this.keySizeSensor = registerSensor(
         keySizeSensorName,

services/venice-server/src/test/java/com/linkedin/venice/stats/AggHostLevelIngestionStatsTest.java

@@ -79,7 +79,6 @@ public void testMetrics() {
     Assert.assertEquals(
         reporter.query(".total--bytes_read_from_kafka_as_uncompressed_size.Rate").value(),
         300d / LongAdderRateGauge.RATE_GAUGE_CACHE_DURATION_IN_SECONDS);
-    Assert.assertEquals(reporter.query("." + STORE_FOO + "--global_store_disk_quota_allowed.Gauge").value(), 200d);
 
     Assert.assertEquals(
         reporter.query(".total--records_consumed.Rate").value(),