Mark error-resilient switch frames as restricted

[xinzhao-apple]

When the encoder is run in error-resilient mode (--global-error-resilient=1), switch frames are emitted without their reference frames being marked as restricted. This produces a bitstream that is not AV2-compliant and that decoders reject.

This MR sets restricted_prediction_switch for error-resilient switch frames as well, so switch frames generated in that mode carry the correct restricted-reference semantics.

In error-resilient mode (--global-error-resilient=1), the current AVM encoder converts alt-ref–type frames (which are reordered/future frames) into switch frames. When such a switch is left unconstrained (non-restricted), the encoder can assign it a low display order hint (e.g. 1) while a frame with a higher display order hint (e.g. 4) has already been output, producing a non-monotonic output order. Because a non-restricted switch does not reset the OrderHint counter, this violates the conformance constraint below (AV2 spec §7.3.6, "Coded extended layer unit"):

If monotonic_output_order_flag is equal to 0, it is a requirement of bitstream conformance that within a coded video sequence, for a given value of obu_xlayer_id and obu_mlayer_id, if a coded output frame unit X has an associated OrderHint value equal to ohX, there shall not be a coded output frame unit Y in the same extended layer and embedded layer that appears later than X in output order and has an associated OrderHint value less than or equal to ohX, unless a switch frame with restricted_prediction_switch equal to 1 appears between X and Y in coding order.
NOTE: The value of OrderHint is reset at the start of a new coded video sequence and at a switch frame with restricted_prediction_switch equal to 1. In both cases, the OrderHint counter is effectively restarted, allowing OrderHint values to be reused in subsequent coded output frame units.