It resolves Broadcast Limitations issue if target API level is changed
as 26 or higher later.
It includes fixing code style also.

Test: Check messaging widgets' changes.

Change-Id: I6e08027b1d6a5a19cfd17f8ec3e9a895dbb3c44a
Signed-off-by: Taesu Lee <taesu82.lee@samsung.com>