Explicitly preload libgomp

libgomp has a long lasting TLS bug
(https://bugzilla.redhat.com/show_bug.cgi?id=1722181). Preload the
library in gst-plugin-scanner to resolve the TLS memory issue while
launching gstreamer.

b/165530393

Change-Id: Ibdde0b7e460567af07a3cc13088126b007919f10