tests: dynappsrc: Add test case for EOS event

Dynappsrc should handle an EOS event that it send to all of linked
appsrce elements.

Change-Id: Ib17db1c8165ad995adec11d2e233753a7bdb845f
Reviewed-on: https://gpro.palm.com/47610
Tested-by: HoonHee Lee <hoonhee.lee@lge.com>
Reviewed-by: Jeongseok Kim <jeongseok.kim@lge.com>
Tested-by: Jeongseok Kim <jeongseok.kim@lge.com>
dynappsrc: EOS event needs to be spread into each source

When receiving EOS event from dynappsrc through a signal,
the event will be sent to the other elements.

Change-Id: I9cc821282b938d97b4c6828cbb2845456bf91ac0
Reviewed-on: https://gpro.palm.com/47611
Reviewed-by: Jeongseok Kim <jeongseok.kim@lge.com>
Tested-by: Jeongseok Kim <jeongseok.kim@lge.com>
tests: dynappsrc: Update test case for EOS event

After sending an EOS event all of appsrc elements, GST_MESSAGE_EOS
should be triggered by bus.

Change-Id: Ied1e70f6a6ac6612eeb2522952f7b5023e583865
Reviewed-on: https://gpro.palm.com/47641
Tested-by: HoonHee Lee <hoonhee.lee@lge.com>
Reviewed-by: Jeongseok Kim <jeongseok.kim@lge.com>
Tested-by: Jeongseok Kim <jeongseok.kim@lge.com>