Improve code coverage of sdp_integration_fuzzer. This originally landed in <https://commits.webkit.org/269551@main>, but was reverted when updating libwebrtc to M120 in <https://commits.webkit.org/271863@main> because I failed to add the `WEBRTC_WEBKIT_BUILD` macros around the new code.
<rdar://problem/120503718>
Pull request: https://github.com/WebKit/WebKit/pull/22413
Committed 272671@main (ea6d6f413312): <https://commits.webkit.org/272671@main> Reviewed commits have been landed. Closing PR #22413 and removing active labels.