gstminiobject: shares capacity increase

gstminiobject: shares capacity increase

during the MSE (WebKit) tests from Apple suite:
https://hls-streaming.cdn-apple.com/hls_conformance/dist/v1.1/index.html?pretty=true&whitelist=MSE%20Suite
webkit attempts to add a single audio buffer containing ~35.5k frames.
when corresponding GstSamples are pulled buffer is being referenced
more than object capacity allows: 2^15-1. since the case could be considered
malformed a surgical patch is applied to increase the capacity.

Part-of: <https://gitlab.freedesktop.org/gstreamer/gstreamer/-/merge_requests/3221>