tests: allow more time for the test_many_bins pipeline to preroll
tests: allow more time for the test_many_bins pipeline to preroll

Hopefully makes this test work on the OSX build bot and other
not-so-powerful machines.

https://bugzilla.gnome.org/show_bug.cgi?id=646624

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