Move LayoutParam secure flag so it's set on the WS level

The LayoutParam secure flag set by the client is set on the WSA level.

This causes a few issues:
1. Child windows don't inherit this flag since child windows are added
   beneath WS
2. Prevents moving the WSA's SC to the client since the secure flag
   needs to be set in WMS.

Test: FlagSecureTest
Bug: 308662081
Change-Id: I724ab0d834b0d74b33ccbb6bbd2c6f9c622c2a15