Fix incorrect snapshotting of MRP config by CASE client.

Right now, we snapshot the MRP config as part of the CASEClientInitParams during stack startup.

After that, we will use that snapshotted config whenever we are the CASE initiator.

This config will not match the parameters we use as CASE responder or advertise
over DNS-SD if the local MRP configuration ever changes.  Which for an ICD it can.

The fix is to stop the incorrect snapshotting and get the information we need
from the right source of truth when we need it.

Author: bzbarsky-apple

src/app/CASEClient.cpp

@@ -50,9 +50,10 @@ CHIP_ERROR CASEClient::EstablishSession(const CASEClientInitParams & params, con
     VerifyOrReturnError(exchange != nullptr, CHIP_ERROR_INTERNAL);
 
     mCASESession.SetGroupDataProvider(params.groupDataProvider);
+    // EstablishSession defaults to using the local MRP config, which is what we want.
     ReturnErrorOnFailure(mCASESession.EstablishSession(*params.sessionManager, params.fabricTable, peer, exchange,
                                                        params.sessionResumptionStorage, params.certificateValidityPolicy, delegate,
-                                                       params.mrpLocalConfig));
+                                                       NullOptional));
 
     return CHIP_NO_ERROR;
 }

src/app/CASEClient.h

@@ -34,7 +34,6 @@ struct CASEClientInitParams
     Messaging::ExchangeManager * exchangeMgr                           = nullptr;
     FabricTable * fabricTable                                          = nullptr;
     Credentials::GroupDataProvider * groupDataProvider                 = nullptr;
-    Optional<ReliableMessageProtocolConfig> mrpLocalConfig             = Optional<ReliableMessageProtocolConfig>::Missing();
 
     CHIP_ERROR Validate() const
     {

src/app/server/Server.cpp

@@ -313,7 +313,6 @@ CHIP_ERROR Server::Init(const ServerInitParams & initParams)
             .exchangeMgr       = &mExchangeMgr,
             .fabricTable       = &mFabrics,
             .groupDataProvider = mGroupsProvider,
-            .mrpLocalConfig    = GetLocalMRPConfig(),
         },
         .clientPool            = &mCASEClientPool,
         .sessionSetupPool      = &mSessionSetupPool,

src/controller/CHIPDeviceControllerFactory.cpp

@@ -270,7 +270,6 @@ CHIP_ERROR DeviceControllerFactory::InitSystemState(FactoryInitParams params)
         .exchangeMgr               = stateParams.exchangeMgr,
         .fabricTable               = stateParams.fabricTable,
         .groupDataProvider         = stateParams.groupDataProvider,
-        .mrpLocalConfig            = GetLocalMRPConfig(),
     };
 
     CASESessionManagerConfig sessionManagerConfig = {