[Android] Update standard protection dropdown on privacy guide

Updates the standard protection summary text and removes the
aux button which leads to an extra page discussing what standard
protection offers. This change uses the visibiltiy attribute of xml to
hide and show views depending on the status of our feature flag.

Screenshots can be found here: https://crbug.com/1470419#c5

Bug: 1470419
Change-Id: I3ab75ce496d4b7c280190ca08ffffba4f7fa1964
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/4752766
Reviewed-by: Javier Castro <jacastro@chromium.org>
Code-Coverage: Findit <findit-for-me@appspot.gserviceaccount.com>
Reviewed-by: Rubin Deliallisi <rubindl@chromium.org>
Commit-Queue: Awad Osman <awado@google.com>
Cr-Commit-Position: refs/heads/main@{#1181473}