Consolidate wildcarded domain_create testdata XMLs

It's simpler to have fewer of these, and it's clearer from callsites if it's
always explicit exactly which domain is being created.

I also removed two irregularities: domain_create.xml included hostnames but
domain_create_wildcard.xml did not, and the former called the domain name
%DOMAIN% whereas the latter called it %HOSTNAME%.

-------------
Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=204956433

javatests/google/registry/flows/testdata/domain_create.xml

@@ -3,7 +3,7 @@
     <create>
       <domain:create
        xmlns:domain="urn:ietf:params:xml:ns:domain-1.0">
-        <domain:name>example.tld</domain:name>
+        <domain:name>%DOMAIN%</domain:name>
         <domain:period unit="y">2</domain:period>
         <domain:ns>
           <domain:hostObj>ns1.example.net</domain:hostObj>

javatests/google/registry/flows/testdata/domain_create_no_hosts_or_dsdata.xml

@@ -3,7 +3,7 @@
     <create>
       <domain:create
        xmlns:domain="urn:ietf:params:xml:ns:domain-1.0">
-        <domain:name>example.tld</domain:name>
+        <domain:name>%DOMAIN%</domain:name>
         <domain:period unit="y">2</domain:period>
         <domain:registrant>jd1234</domain:registrant>
         <domain:contact type="admin">sh8013</domain:contact>

javatests/google/registry/flows/testdata/domain_create_wildcard.xml

@@ -1,18 +0,0 @@
-<epp xmlns="urn:ietf:params:xml:ns:epp-1.0">
-  <command>
-    <create>
-      <domain:create
-          xmlns:domain="urn:ietf:params:xml:ns:domain-1.0">
-        <domain:name>%HOSTNAME%</domain:name>
-        <domain:period unit="y">2</domain:period>
-        <domain:registrant>jd1234</domain:registrant>
-        <domain:contact type="admin">sh8013</domain:contact>
-        <domain:contact type="tech">sh8013</domain:contact>
-        <domain:authInfo>
-          <domain:pw>2fooBAR</domain:pw>
-        </domain:authInfo>
-      </domain:create>
-    </create>
-    <clTRID>ABC-12345</clTRID>
-  </command>
-</epp>