Hi,
There is guidance to manually upgrade gstreamer version:
https://docs.nvidia.com/jetson/l4t/index.html#page/Tegra%2520Linux%2520Driver%2520Package%2520Development%2520Guide%2Faccelerated_gstreamer.html%23wwpID0E06E0HA
However, the releases are tested with 1.14.5, there could be stability issue if upgrading to another version.
The next r32.5 is still in 1.14.5. We will evaluate upgrading gstreamer version.