Get change API after change update in integration tests

Re-using pre change modification change API results in stale results and
turns some integration tests to be false-negative.
Ensure that new change API ref is obtained after each change update os
that current state could be examined.

Bug: Issue 347739666
Change-Id: I916672707289f3bf1ffd50af76eba08634d9477e

owners/src/test/java/com/googlesource/gerrit/owners/OwnersSubmitRequirementITAbstract.java

diff --git a/owners/src/test/java/com/googlesource/gerrit/owners/OwnersSubmitRequirementITAbstract.java b/owners/src/test/java/com/googlesource/gerrit/owners/OwnersSubmitRequirementITAbstract.java
index 9fc1220..45f65e2 100644
--- a/owners/src/test/java/com/googlesource/gerrit/owners/OwnersSubmitRequirementITAbstract.java
+++ b/owners/src/test/java/com/googlesource/gerrit/owners/OwnersSubmitRequirementITAbstract.java
@@ -103,7 +103,7 @@
     assertThat(changeNotReady.requirements).isEmpty();
 
     changeApi.current().review(ReviewInput.approve());
-    ChangeInfo changeReady = changeApi.get();
+    ChangeInfo changeReady = forChange(r).get();
     assertThat(changeReady.submittable).isTrue();
     assertThat(changeReady.requirements).isEmpty();
   }
@@ -184,9 +184,10 @@
         forChange(r).get().submitRecords, LabelId.VERIFIED, SubmitRecordInfo.Label.Status.NEED);
 
     changeApi.current().review(new ReviewInput().label(LabelId.VERIFIED, 1));
-    assertThat(changeApi.get().submittable).isTrue();
+    ChangeInfo changeReady = forChange(r).get();
+    assertThat(changeReady.submittable).isTrue();
     verifyHasSubmitRecord(
-        changeApi.get().submitRecords, LabelId.VERIFIED, SubmitRecordInfo.Label.Status.OK);
+        changeReady.submitRecords, LabelId.VERIFIED, SubmitRecordInfo.Label.Status.OK);
   }
 
   @Test
@@ -316,7 +317,7 @@
 
     requestScopeOperations.setApiUser(admin2.id());
     forChange(r).current().review(ReviewInput.recommend());
-    ChangeInfo ownersVoteNotSufficient = changeApi.get();
+    ChangeInfo ownersVoteNotSufficient = forChange(r).get();
     assertThat(ownersVoteNotSufficient.submittable).isFalse();
     assertThat(ownersVoteNotSufficient.requirements).containsExactly(READY);
     verifyHasSubmitRecord(