Merge "Update MediaMuxer javadoc to reflect that B-frame muxing is supported since Android Nougat MR1." into main am: 9e36084a54 am: 9c287dbef9

Original change: https://android-review.googlesource.com/c/platform/frameworks/base/+/3300935

Change-Id: I70908e482ead11e87343203bf087e35611d79721
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>