LiveCoding: Fix the "Show Console" button being disabled until the first compile.

#rb none
#jira UE-71379

#ROBOMERGE-OWNER: lina.halper
#ROBOMERGE-AUTHOR: ben.marsh
#ROBOMERGE-SOURCE: CL 5362145 in //UE4/Release-4.22/... via CL 5368489
#ROBOMERGE-BOT: ANIM (Main -> Dev-Anim)

[CL 5381907 by ben marsh in Dev-Anim branch]

Engine/Source/Developer/Windows/LiveCoding/Private/LiveCodingModule.cpp

@@ -226,6 +226,7 @@ bool FLiveCodingModule::StartLiveCoding()
 
 		// Mark it as started
 		bStarted = true;
+		bEnabledForSession = true;
 	}
 	return true;
 }