Increase buffer capacity for mutableRouterEvents flow within RibEvents

[RahulDMello]

Increase buffer capacity for mutableRouterEvents flow within RibEvents.

Description: The RibEvents flow is consumed by the ribtree plugin. However, that consumption can sometimes be slower than production so we were losing a few events. Making a large buffer size helps fix that.

[CLAassistant]

All committers have signed the CLA.

[psteiger]

@tyvsmith can you help w/ getting this merged, please? I see the following message:

Merging is blocked The base branch restricts merging to authorized users

I'm using my personal GitHub account.

cc @dmellorahul

[tyvsmith]

@tyvsmith can you help w/ getting this merged, please? I see the following message:

Merging is blocked The base branch restricts merging to authorized users

I'm using my personal GitHub account.

cc @dmellorahul

Done, and fixed the issue with your access.