revert flaky test changes

Change-Id: I8e0ad310444c754df71dc61782b23d007bbfdaba

Author: nicholsl

google-cloud-bigtable/src/test/java/com/google/cloud/bigtable/data/v2/stub/metrics/BuiltinMetricsTracerTest.java

@@ -708,7 +708,7 @@ public void testQueuedOnChannelServerStreamLatencies() throws Exception {
         .isAtLeast(
             // Offset the expected latency to deal with asynchrony and jitter
             CHANNEL_BLOCKING_LATENCY.minus(
-                Comparators.max(proxyDelayPriorTest, Duration.ofMillis(20))));
+                Comparators.max(proxyDelayPriorTest, Duration.ofMillis(1))));
   }
 
   @Test
@@ -734,7 +734,7 @@ public void testQueuedOnChannelUnaryLatencies() throws Exception {
         .isAtLeast(
             // Offset the expected latency to deal with asynchrony and jitter
             CHANNEL_BLOCKING_LATENCY.minus(
-                Comparators.max(proxyDelayPriorTest, Duration.ofMillis(20))));
+                Comparators.max(proxyDelayPriorTest, Duration.ofMillis(1))));
   }
 
   @Test