Revert "wifidisplay: restrict broadcast by the proper permission"

This reverts commit cff8340c.

Reason for revert: Remove from July 2021 Android Security Bulletin due to break existing applications.

Bug: 176541017
Change-Id: Iacef744056630e85fb43d838a72abfae331cbaf4
Test: install WFD application and check whether it works normally.
(cherry picked from commit 955b64a6)