[Signin][Android] Disable sign-in button on Google Play services error

Disable 'Yes, I'm in' button in the sign-in screen if
AccountManagerFacade couldn't obtain accounts due to Google Play
services error. mHasGmsError is already checked
SigninFragmentBase.areControlsEnabled, so click will be ignored either
way. In this case, making the button actually disabled should reduce
the confusion.

Bug: 997218
Change-Id: Icc84b82290e3df981afe7b6a4871a84e53a31735
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1807326
Commit-Queue: Alex Ilin <alexilin@chromium.org>
Auto-Submit: Boris Sazonov <bsazonov@chromium.org>
Reviewed-by: Alex Ilin <alexilin@chromium.org>
Cr-Commit-Position: refs/heads/master@{#697249}

chrome/android/java/src/org/chromium/chrome/browser/signin/SigninFragmentBase.java

@@ -587,7 +587,8 @@ public abstract class SigninFragmentBase
 
         mAccountNames = getAccountNames(maybeAccountNames);
         mHasGmsError = mAccountNames == null;
-        if (mAccountNames == null) return;
+        mView.getAcceptButton().setEnabled(!mHasGmsError);
+        if (mHasGmsError) return;
 
         if (mAccountNames.isEmpty()) {
             mSelectedAccountName = null;