Change DomainApplication to store period instead of year

-------------
Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=137426843

java/google/registry/flows/domain/DomainApplicationCreateFlow.java

@@ -219,7 +219,7 @@ public final class DomainApplicationCreateFlow extends LoggedInFlow implements T
         .setLaunchNotice(launchCreate == null ? null : launchCreate.getNotice())
         .setIdnTableName(idnTableName)
         .setPhase(launchCreate.getPhase())
-        .setYears(command.getPeriod().getValue())
+        .setPeriod(command.getPeriod())
         .setApplicationStatus(ApplicationStatus.VALIDATED)
         .addStatusValue(StatusValue.PENDING_CREATE)
         .setDsData(secDnsCreate == null ? null : secDnsCreate.getDsData())

java/google/registry/model/domain/DomainApplication.java

@@ -69,9 +69,9 @@ public class DomainApplication extends DomainBase {
   @XmlTransient
   LaunchPhase phase;
 
-  /** The requested number of years of registration. */
+  /** The requested registration period. */
   @XmlTransient
-  int years;
+  Period period;
   
   /** The current status of this application. */
   @XmlTransient
@@ -98,8 +98,8 @@ public class DomainApplication extends DomainBase {
     return phase;
   }
 
-  public int getYears() {
-    return years;
+  public Period getPeriod() {
+    return period;
   }
 
   public ApplicationStatus getApplicationStatus() {
@@ -159,8 +159,8 @@ public class DomainApplication extends DomainBase {
       return this;
     }
     
-    public Builder setYears(int years) {
-      getInstance().years = years;
+    public Builder setPeriod(Period period) {
+      getInstance().period = period;
       return this;
     }