Remove resetAccountManagerHelperForTests() since it caused test failures

chrome/test/android/javatests/src/org/chromium/chrome/test/util/browser/signin/SigninTestUtil.java

Index: chrome/test/android/javatests/src/org/chromium/chrome/test/util/browser/signin/SigninTestUtil.java
diff --git a/chrome/test/android/javatests/src/org/chromium/chrome/test/util/browser/signin/SigninTestUtil.java b/chrome/test/android/javatests/src/org/chromium/chrome/test/util/browser/signin/SigninTestUtil.java
index 1f35e12533cd73cfb77dec282715b6170c48eea3..583376ca89798e6f3ad68e8e03e7e16570a3f75d 100644
--- a/chrome/test/android/javatests/src/org/chromium/chrome/test/util/browser/signin/SigninTestUtil.java
+++ b/chrome/test/android/javatests/src/org/chromium/chrome/test/util/browser/signin/SigninTestUtil.java
@@ -59,7 +59,6 @@ public final class SigninTestUtil {
      * Tears down the test authentication environment.
      */
     public static void tearDownAuthForTest() {
-        AccountManagerHelper.resetAccountManagerHelperForTests();
         sContext = null;
     }