[AVFoundation] Fix nullability in some delegate signatures.

[mandel-macaque]

Some of the delegates in the framework were wrong.

[vs-mobiletools-engineering-service2]

🔥 [CI Build #a4446f8] Test results 🔥

Test results

❌ Tests failed on VSTS: test results

1 tests crashed, 0 tests failed, 114 tests passed.

Failures

❌ dotnettests tests (macOS)

🔥 Failed catastrophically on VSTS: test results - dotnettests_macos (no summary found).

Html Report (VSDrops) Download

Successes

✅ cecil: All 1 tests passed. Html Report (VSDrops) Download
✅ dotnettests (iOS): All 1 tests passed. Html Report (VSDrops) Download
✅ dotnettests (MacCatalyst): All 1 tests passed. Html Report (VSDrops) Download
✅ dotnettests (Multiple platforms): All 1 tests passed. Html Report (VSDrops) Download
✅ dotnettests (tvOS): All 1 tests passed. Html Report (VSDrops) Download
✅ framework: All 2 tests passed. Html Report (VSDrops) Download
✅ fsharp: All 4 tests passed. Html Report (VSDrops) Download
✅ generator: All 5 tests passed. Html Report (VSDrops) Download
✅ interdependent-binding-projects: All 4 tests passed. Html Report (VSDrops) Download
✅ introspection: All 4 tests passed. Html Report (VSDrops) Download
✅ linker: All 44 tests passed. Html Report (VSDrops) Download
✅ monotouch (iOS): All 8 tests passed. Html Report (VSDrops) Download
✅ monotouch (MacCatalyst): All 11 tests passed. Html Report (VSDrops) Download
✅ monotouch (macOS): All 9 tests passed. Html Report (VSDrops) Download
✅ monotouch (tvOS): All 8 tests passed. Html Report (VSDrops) Download
✅ msbuild: All 2 tests passed. Html Report (VSDrops) Download
✅ windows: All 3 tests passed. Html Report (VSDrops) Download
✅ xcframework: All 4 tests passed. Html Report (VSDrops) Download
✅ xtro: All 1 tests passed. Html Report (VSDrops) Download

Pipeline on Agent
Hash: a4446f876598d3370dff2cc8473ca98fba1b94bc [PR build]

[vs-mobiletools-engineering-service2]

✅ [CI Build #7efefa5] Build passed (Build packages) ✅

Pipeline on Agent
Hash: 7efefa5ffef402c991417dbe7ae8ad8a3ca8c4a1 [PR build]

[vs-mobiletools-engineering-service2]

✅ [PR Build #7efefa5] Build passed (Detect API changes) ✅

Pipeline on Agent
Hash: 7efefa5ffef402c991417dbe7ae8ad8a3ca8c4a1 [PR build]

[vs-mobiletools-engineering-service2]

✅ API diff for current PR / commit

.NET ( No breaking changes )

• iOS: vsdrops gist ( No breaking changes )
• tvOS: vsdrops gist ( No breaking changes )
• MacCatalyst: vsdrops gist ( No breaking changes )
• macOS: vsdrops gist ( No breaking changes )

✅ API diff vs stable

.NET ( No breaking changes )

• iOS: vsdrops gist ( No breaking changes )
• tvOS: vsdrops gist ( No breaking changes )
• MacCatalyst: vsdrops gist ( No breaking changes )
• macOS: vsdrops gist ( No breaking changes )

ℹ️ Generator diff

Generator Diff: vsdrops (html) vsdrops (raw diff) gist (raw diff) - Please review changes)

Pipeline on Agent
Hash: 7efefa5ffef402c991417dbe7ae8ad8a3ca8c4a1 [PR build]

[vs-mobiletools-engineering-service2]

✅ [CI Build #7efefa5] Build passed (Build macOS tests) ✅

Pipeline on Agent
Hash: 7efefa5ffef402c991417dbe7ae8ad8a3ca8c4a1 [PR build]

[vs-mobiletools-engineering-service2]

💻 [CI Build #7efefa5] Tests on macOS X64 - Mac Sonoma (14) passed 💻

✅ All tests on macOS X64 - Mac Sonoma (14) passed.

Pipeline on Agent
Hash: 7efefa5ffef402c991417dbe7ae8ad8a3ca8c4a1 [PR build]

[vs-mobiletools-engineering-service2]

💻 [CI Build #7efefa5] Tests on macOS M1 - Mac Ventura (13) passed 💻

✅ All tests on macOS M1 - Mac Ventura (13) passed.

Pipeline on Agent
Hash: 7efefa5ffef402c991417dbe7ae8ad8a3ca8c4a1 [PR build]

[vs-mobiletools-engineering-service2]

💻 [CI Build #7efefa5] Tests on macOS arm64 - Mac Sequoia (15) passed 💻

✅ All tests on macOS arm64 - Mac Sequoia (15) passed.

Pipeline on Agent
Hash: 7efefa5ffef402c991417dbe7ae8ad8a3ca8c4a1 [PR build]

[vs-mobiletools-engineering-service2]

💻 [CI Build #7efefa5] Tests on macOS M1 - Mac Monterey (12) passed 💻

✅ All tests on macOS M1 - Mac Monterey (12) passed.

Pipeline on Agent
Hash: 7efefa5ffef402c991417dbe7ae8ad8a3ca8c4a1 [PR build]

[mandel-macaque]

Failing tests are unrelated to the code changes.