Revert "Revert "Revert "Turning on flag to enforce dynamically registered...

Revert "Revert "Revert "Turning on flag to enforce dynamically registered receiver requirement of specifying one of RECEIVER_EXPORTED and RECEIVER_NOT_EXPORTED for non system broadcasts."""

This reverts commit cf7f1c89.

Reason for revert: This is causing several WebView CTS failures.

Change-Id: Ib3438f12ddc240268fa128f88029b03aac28d4d1