Code-owners plugin adaptations for: make TestMetricMaker a real singleton

Verification is manually overriden for this change as the automation doesn't use the main `gerrit/gerrit` change. Both changes will be submitted together as part of the same topic.

Main change: I07739b44d22c0d2d7cb257443551478c458d7daf
Release-Notes: skip
Google-Bug: b/443200063

Change-Id: I1079747355eb006a4028c128629b6327355fa831

javatests/com/google/gerrit/plugins/codeowners/acceptance/api/CodeOwnerSubmitRuleIT.java

diff --git a/javatests/com/google/gerrit/plugins/codeowners/acceptance/api/CodeOwnerSubmitRuleIT.java b/javatests/com/google/gerrit/plugins/codeowners/acceptance/api/CodeOwnerSubmitRuleIT.java
index 1769dce..7275f4f 100644
--- a/javatests/com/google/gerrit/plugins/codeowners/acceptance/api/CodeOwnerSubmitRuleIT.java
+++ b/javatests/com/google/gerrit/plugins/codeowners/acceptance/api/CodeOwnerSubmitRuleIT.java
@@ -59,9 +59,9 @@
 
 /** Acceptance test for {@code com.google.gerrit.plugins.codeowners.backend.CodeOwnerSubmitRule}. */
 public class CodeOwnerSubmitRuleIT extends AbstractCodeOwnersIT {
+  private final TestMetricMaker testMetricMaker = TestMetricMaker.getInstance();
   @Inject private RequestScopeOperations requestScopeOperations;
   @Inject private ProjectOperations projectOperations;
-  @Inject private TestMetricMaker testMetricMaker;
 
   @Test
   public void changeIsSubmittableIfCodeOwnersFuctionalityIsDisabled() throws Exception {

javatests/com/google/gerrit/plugins/codeowners/backend/CodeOwnerResolverTest.java

diff --git a/javatests/com/google/gerrit/plugins/codeowners/backend/CodeOwnerResolverTest.java b/javatests/com/google/gerrit/plugins/codeowners/backend/CodeOwnerResolverTest.java
index 7fc6cec..9d60b03 100644
--- a/javatests/com/google/gerrit/plugins/codeowners/backend/CodeOwnerResolverTest.java
+++ b/javatests/com/google/gerrit/plugins/codeowners/backend/CodeOwnerResolverTest.java
@@ -48,11 +48,12 @@
   private static final ObjectId TEST_REVISION =
       ObjectId.fromString("deadbeefdeadbeefdeadbeefdeadbeefdeadbeef");
 
+  private final TestMetricMaker testMetricMaker = TestMetricMaker.getInstance();
+
   @Inject private RequestScopeOperations requestScopeOperations;
   @Inject @ServerInitiated private Provider<AccountsUpdate> accountsUpdate;
   @Inject private AccountOperations accountOperations;
   @Inject private ExternalIdNotes.Factory externalIdNotesFactory;
-  @Inject private TestMetricMaker testMetricMaker;
   @Inject private ExternalIdFactory externalIdFactory;
 
   private Provider<CodeOwnerResolver> codeOwnerResolverProvider;