ElasticVersion: Say 'Unsupported' rather than 'Invalid'

If a version number is not recognized, it is not necessarily invalid,
but could just be because we didn't yet add support for it.

Change the error message to be less aggressive.

Change-Id: I904ff165b7e04ae0c5e7514923a75f6a74e8b005
diff --git a/gerrit-elasticsearch/src/main/java/com/google/gerrit/elasticsearch/ElasticVersion.java b/gerrit-elasticsearch/src/main/java/com/google/gerrit/elasticsearch/ElasticVersion.java
index 3cae775..364e069 100644
--- a/gerrit-elasticsearch/src/main/java/com/google/gerrit/elasticsearch/ElasticVersion.java
+++ b/gerrit-elasticsearch/src/main/java/com/google/gerrit/elasticsearch/ElasticVersion.java
@@ -31,23 +31,23 @@
     this.pattern = Pattern.compile(version);
   }
 
-  public static class InvalidVersion extends ElasticException {
+  public static class UnsupportedVersion extends ElasticException {
     private static final long serialVersionUID = 1L;
 
-    InvalidVersion(String version) {
+    UnsupportedVersion(String version) {
       super(
           String.format(
-              "Invalid version: [%s]. Supported versions: %s", version, supportedVersions()));
+              "Unsupported version: [%s]. Supported versions: %s", version, supportedVersions()));
     }
   }
 
-  public static ElasticVersion forVersion(String version) throws InvalidVersion {
+  public static ElasticVersion forVersion(String version) throws UnsupportedVersion {
     for (ElasticVersion value : ElasticVersion.values()) {
       if (value.pattern.matcher(version).matches()) {
         return value;
       }
     }
-    throw new InvalidVersion(version);
+    throw new UnsupportedVersion(version);
   }
 
   public static String supportedVersions() {
diff --git a/gerrit-elasticsearch/src/test/java/com/google/gerrit/elasticsearch/ElasticVersionTest.java b/gerrit-elasticsearch/src/test/java/com/google/gerrit/elasticsearch/ElasticVersionTest.java
index d4e5695..502c865 100644
--- a/gerrit-elasticsearch/src/test/java/com/google/gerrit/elasticsearch/ElasticVersionTest.java
+++ b/gerrit-elasticsearch/src/test/java/com/google/gerrit/elasticsearch/ElasticVersionTest.java
@@ -41,9 +41,9 @@
 
   @Test
   public void unsupportedVersion() throws Exception {
-    exception.expect(ElasticVersion.InvalidVersion.class);
+    exception.expect(ElasticVersion.UnsupportedVersion.class);
     exception.expectMessage(
-        "Invalid version: [4.0.0]. Supported versions: " + ElasticVersion.supportedVersions());
+        "Unsupported version: [4.0.0]. Supported versions: " + ElasticVersion.supportedVersions());
     ElasticVersion.forVersion("4.0.0");
   }