[Signin][Android] Remove redundant check for old Robolectric

This CL removes a null check for Robolectic version < 3.7. Since our
current Robolectric version is 4.3, we don't need this check anymore.

Bug: 779568
Change-Id: I6a325a807304efb3769c5291e82c127250ecdb66
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2152835Reviewed-by: Boris Sazonov <bsazonov@chromium.org>
Commit-Queue: Alice Wang <aliceywang@chromium.org>
Cr-Commit-Position: refs/heads/master@{#760568}

components/signin/core/browser/android/java/src/org/chromium/components/signin/AccountManagerFacadeImpl.java

@@ -406,10 +406,6 @@ public class AccountManagerFacadeImpl implements AccountManagerFacade {
         Context context = ContextUtils.getApplicationContext();
         UserManager userManager = (UserManager) context.getSystemService(Context.USER_SERVICE);
         Bundle appRestrictions = userManager.getApplicationRestrictions(context.getPackageName());
-        // TODO(https://crbug.com/779568): Remove this after migrating to Robolectric 3.7+.
-        // Android guarantees that getApplicationRestrictions result won't be null, but
-        // Robolectric versions 3.6 and older don't respect this.
-        if (appRestrictions == null) appRestrictions = new Bundle();
         return appRestrictions.getStringArray(ACCOUNT_RESTRICTION_PATTERNS_KEY);
     }