Revert "wifidisplay: restrict broadcast by the proper permission"

This reverts commit 1d4c97ff.

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

Bug: 176541017
Change-Id: I4d12bbccc30cd572b55cba2b98154b96e590136d
Test: install WFD application and check whether it works normally.