dashboard: reduce expected number of corellium builders to 2 each

According to https://golang.org/issue/40523#issuecomment-676546824,
there are only 2 Android corellium hosts and 2 iOS corellium hosts.

Also add links to issues with more information to the builder notes.

Updates golang/go#40523.
Updates golang/go#31722.

Change-Id: Ibabccebfcc6735cba867cccf109c71607223d1a2
Reviewed-on: https://go-review.googlesource.com/c/build/+/249337
Reviewed-by: Carlos Amedee <carlos@golang.org>
diff --git a/dashboard/builders.go b/dashboard/builders.go
index 1367b9e..358fe65 100644
--- a/dashboard/builders.go
+++ b/dashboard/builders.go
@@ -562,19 +562,19 @@
 		},
 	},
 	"host-darwin-arm64-corellium-ios": &HostConfig{
-		Notes:       "Virtual iOS devices hosted by Zenly on Corellium",
+		Notes:       "Virtual iOS devices hosted by Zenly on Corellium; see issues 31722 and 40523",
 		OwnerGithub: "znly",
 		IsReverse:   true,
-		ExpectNum:   3,
+		ExpectNum:   2,
 		env: []string{
 			"GOROOT_BOOTSTRAP=/var/mobile/go-darwin-arm64-bootstrap",
 		},
 	},
 	"host-android-arm64-corellium-android": &HostConfig{
-		Notes:       "Virtual Android devices hosted by Zenly on Corellium",
+		Notes:       "Virtual Android devices hosted by Zenly on Corellium; see issues 31722 and 40523",
 		OwnerGithub: "znly",
 		IsReverse:   true,
-		ExpectNum:   3,
+		ExpectNum:   2,
 		env: []string{
 			"GOROOT_BOOTSTRAP=/data/data/com.termux/files/home/go-android-arm64-bootstrap",
 		},