AV1 Encoder: Add AV1 to supported types of MediaRecorder

Adds AV1 to supported types of MediaRecorder and fixes MP4 writer

Bug: b/285972478
Test: atest MediaRecorderTest#testAV1SDRecording
(cherry picked from https://googleplex-android-review.googlesource.com/q/commit:03dd7d46d318ae05a1466ceb87b01a34e057337e)
Merged-In: I8292665f21f3f836a0f67891322cfee41d78f327
Change-Id: I8292665f21f3f836a0f67891322cfee41d78f327
2 files changed