Amazon Kinesis Video Streams Media Interface Release v1.2.1

What's Changed

• webrtc: merge amazon-kinesis-video-streams-webrtc-sdk-c/pull/1448 by @codingspirit in #61
• webrtc: upgrade to v1.7.3 by @codingspirit in #62
• github actions: allow to trigger workflow manually by @codingspirit in #64
• doc: add details guides about using AK/SK and IoT certificate by @codingspirit in #65
• webrtc: fix possible patch error when build more than once by @codingspirit in #66
• Release v1.2.1 by @codingspirit in #68

Full Changelog: v1.1.0...v1.2.1