Implement getMediaPipeline

Change-Id: I34b7b8e017d14436dcc2bba6b4a9672c27811e4d
Add test for checking same token

Change-Id: I4543b2bdfca02c79d0610728285272a4ff61d536
Update kms-interface

Change-Id: I6674a32cb57b7ea0f0f97baac25b266e91582ca9
Add test for getting parent of a MediaPipeline

Change-Id: Ief855b6f66013d5bd231d3639b779bf3f2699378
Delete old and useless tests

Change-Id: I6542e58bc9cf786605ecb0215a66ed70d61857b1
Add static constructor in MediaSet to init GST log

Change-Id: Ifa721ec037f45eff3766cdba6af5be877c99c486
Implement auto release and keepalive

Change-Id: Idf500a776e6400f0082cf79b68d28d259b19b9c2