Prevent crash when AutofillManager.isEnabled() is called

If we cannot get flag information from the AutofillManagerService
after the timeout, we should not crash the process, we need to
handle the enabled information properly.

Also fix NPE because of null component name while calling
AutofillManagerServiceImpl.isWhitelistedForAugmentedAutofillLocked().

Bug: 151273845
Test: atest CtsAutoFillServiceTestCases
Test: manual. Copy the text from Messenger and paste on search bar,
no crash occurred and can paste text correctly.

Change-Id: I8d7ca35226052944fd68fef60a013a65a7fb57c1