Deprecates setContext() and moves the required Context arg into the constructor. This way, the parameter can later be final and non-null, per the comment at: http://go/https://github.com/google/ExoPlayer/commit/ecb47ba5647a7622fc73c09ac37f4e8b3b450cec/depot/google3/third_party/java_src/android_libs/media/libraries/transformer/src/main/java/androidx/media3/transformer/TranscodingTransformer.java?left=s19&right=r12#97L Also, fixes setOutputMimeType_unsupportedMimeType_throws by providing a context in the builder, and updating the FrameworkMuxer#supportsOutputMimeType to catch IllegalArgumentExceptions thrown by FrameworkMuxer#mimeTypeToMuxerOutputFormat. PiperOrigin-RevId: 412053564
