[Android][Test] Refactor SyncTestRule#setUpAccountAndSignInForTesting()

This CL refactors SyncTestRule#setUpAccountAndSignInForTesting() by
using AccountManagerTestRule to handle the sign-in instead of handling
it directly in SyncTestRule.

Bug: 1126814
Change-Id: Ib8c3941ecad3642f6749915142562d68a8ff4a5c
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2401345
Commit-Queue: Alice Wang <aliceywang@chromium.org>
Reviewed-by: Marc Treib <treib@chromium.org>
Cr-Commit-Position: refs/heads/master@{#805743}

chrome/android/javatests/src/org/chromium/chrome/browser/sync/SyncTestRule.java

@@ -202,8 +202,10 @@ public class SyncTestRule extends ChromeActivityTestRule<ChromeActivity> {
      * @return the test account that is signed in.
      */
     public Account setUpAccountAndSignInForTesting() {
-        Account account = addTestAccount();
-        signinAndEnableSync(account);
+        Account account = mAccountManagerTestRule.addAndSignInTestAccount(mProfileSyncService);
+        enableUKM();
+        SyncTestUtil.waitForSyncActive();
+        SyncTestUtil.triggerSyncAndWaitForCompletion();
         return account;
     }
 
@@ -429,10 +431,8 @@ public class SyncTestRule extends ChromeActivityTestRule<ChromeActivity> {
                                     Assert.fail("Sign-in was aborted");
                                 }
                             });
-            // Outside of tests, URL-keyed anonymized data collection is enabled by sign-in UI.
-            UnifiedConsentServiceBridge.setUrlKeyedAnonymizedDataCollectionEnabled(
-                    Profile.getLastUsedRegularProfile(), true);
         });
+        enableUKM();
         if (setFirstSetupComplete) {
             SyncTestUtil.waitForSyncActive();
             SyncTestUtil.triggerSyncAndWaitForCompletion();
@@ -441,4 +441,12 @@ public class SyncTestRule extends ChromeActivityTestRule<ChromeActivity> {
         }
         Assert.assertEquals(account, mAccountManagerTestRule.getCurrentSignedInAccount());
     }
+
+    private static void enableUKM() {
+        TestThreadUtils.runOnUiThreadBlocking(() -> {
+            // Outside of tests, URL-keyed anonymized data collection is enabled by sign-in UI.
+            UnifiedConsentServiceBridge.setUrlKeyedAnonymizedDataCollectionEnabled(
+                    Profile.getLastUsedRegularProfile(), true);
+        });
+    }
 }