pipeline: Take start_time after chaining up too
pipeline: Take start_time after chaining up too

Refactor the code to take the current start_time when going to PAUSED.
Make sure we also call the start_time update code after we chained up to the
parent bin.

Fixes #607842

krichter722/gstreamer,mparis/gstreamer,collects/gstreamer,cfoch/gstreamer,cfoch/gstreamer,krichter722/gstreamer,shelsonjava/gstreamer,surround-io/gstreamer,surround-io/gstreamer,jpakkane/gstreamer,krieger-od/gstreamer,collects/gstreamer,lubosz/gstreamer,Distrotech/gstreamer,collects/gstreamer,ensonic/gstreamer,centricular/gstreamer,drothlis/gstreamer,cablelabs/gstreamer,Lachann/gstreamer,jpxiong/gstreamer,cfoch/gstreamer,ahmedammar/platform_external_gst_gstreamer,StreamUtils/gstreamer,lovebug356/gstreamer,ensonic/gstreamer,krichter722/gstreamer,Lachann/gstreamer,magcius/gstreamer,surround-io/gstreamer,jpxiong/gstreamer,lovebug356/gstreamer,surround-io/gstreamer,centricular/gstreamer,mparis/gstreamer,jpakkane/gstreamer,cfoch/gstreamer,StreamUtils/gstreamer,shelsonjava/gstreamer,mrchapp/gstreamer,Distrotech/gstreamer,jpxiong/gstreamer,shelsonjava/gstreamer,Lachann/gstreamer,justinjoy/gstreamer,mrchapp/gstreamer,ahmedammar/platform_external_gst_gstreamer,ahmedammar/platform_external_gst_gstreamer,cablelabs/gstreamer,jpxiong/gstreamer,mparis/gstreamer,Lachann/gstreamer,StreamUtils/gstreamer,Lachann/gstreamer,mrchapp/gstreamer,StreamUtils/gstreamer,Distrotech/gstreamer,surround-io/gstreamer,krieger-od/gstreamer,Distrotech/gstreamer,drothlis/gstreamer,justinjoy/gstreamer,magcius/gstreamer,magcius/gstreamer,jpxiong/gstreamer,cablelabs/gstreamer,Distrotech/gstreamer,krieger-od/gstreamer,drothlis/gstreamer,cablelabs/gstreamer,ylatuya/gstreamer,lubosz/gstreamer,ahmedammar/platform_external_gst_gstreamer,ylatuya/gstreamer,cablelabs/gstreamer,krieger-od/gstreamer,lubosz/gstreamer,jpakkane/gstreamer,cfoch/gstreamer,ylatuya/gstreamer,centricular/gstreamer,lovebug356/gstreamer,mparis/gstreamer,lubosz/gstreamer,mrchapp/gstreamer,magcius/gstreamer,ylatuya/gstreamer,justinjoy/gstreamer,lovebug356/gstreamer,krieger-od/gstreamer,shelsonjava/gstreamer,centricular/gstreamer,mrchapp/gstreamer,krichter722/gstreamer,lovebug356/gstreamer,mparis/gstreamer,jpakkane/gstreamer,krichter722/gstreamer,StreamUtils/gstreamer,centricular/gstreamer,drothlis/gstreamer,drothlis/gstreamer,justinjoy/gstreamer,ahmedammar/platform_external_gst_gstreamer,collects/gstreamer,magcius/gstreamer,jpakkane/gstreamer,lubosz/gstreamer,ensonic/gstreamer,collects/gstreamer,ensonic/gstreamer,justinjoy/gstreamer,ensonic/gstreamer,ylatuya/gstreamer,shelsonjava/gstreamer