Revert "Expose getSearchBox from the HomeAllApps class"

Revert submission 20714047-b_255390519

Reason for revert: broken test b/266169958 (P0 bug) and broken UI for the EDU card

Reverted changes: /q/submissionid:20714047-b_255390519

Change-Id: I250003c1b3d07637dde596225f08a6bd3cb84365
6 files changed