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).

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

java/google/registry/model/domain/Period.java

@@ -14,7 +14,6 @@
 
 package google.registry.model.domain;
 
-
 import com.googlecode.objectify.annotation.Embed;
 import google.registry.model.ImmutableObject;
 import javax.xml.bind.annotation.XmlAttribute;

java/google/registry/model/domain/metadata/package-info.java

@@ -24,4 +24,3 @@ import javax.xml.bind.annotation.XmlAccessorType;
 import javax.xml.bind.annotation.XmlNs;
 import javax.xml.bind.annotation.XmlNsForm;
 import javax.xml.bind.annotation.XmlSchema;
-

java/google/registry/model/domain/rgp/package-info.java

@@ -24,4 +24,3 @@ import javax.xml.bind.annotation.XmlAccessorType;
 import javax.xml.bind.annotation.XmlNs;
 import javax.xml.bind.annotation.XmlNsForm;
 import javax.xml.bind.annotation.XmlSchema;
-

java/google/registry/model/domain/secdns/package-info.java

@@ -24,4 +24,3 @@ import javax.xml.bind.annotation.XmlAccessorType;
 import javax.xml.bind.annotation.XmlNs;
 import javax.xml.bind.annotation.XmlNsForm;
 import javax.xml.bind.annotation.XmlSchema;
-