Fix Settings crash when activity is null

in ManageApplications, if getActivity is null, it will cause crash
because in HelpUtils#prepareHelpMenuItem it will call activity's
getString method.

Test: manual
Change-Id: I4c9cf985e94192a936d195ea4279ec1d0f22eb10
Signed-off-by: songkailun <songkailun@xiaomi.com>
1 file changed