Format some imports using fix_imports.py

Unfortunately this tool isn't smart enough to deal with the assertThat
situation (which has two static imports of a function with the same name).

-------------
Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=172000753

java/google/registry/monitoring/metrics/AbstractMetric.java

@@ -14,7 +14,6 @@
 
 package google.registry.monitoring.metrics;
 
-
 import com.google.common.base.MoreObjects;
 import com.google.common.collect.ImmutableSet;
 import google.registry.monitoring.metrics.MetricSchema.Kind;

java/google/registry/monitoring/metrics/StoredMetric.java

@@ -14,7 +14,6 @@
 
 package google.registry.monitoring.metrics;
 
-
 import com.google.common.annotations.VisibleForTesting;
 import com.google.common.collect.ImmutableList;
 import com.google.common.collect.ImmutableList.Builder;