[roll] Roll sdk-core packages to version:6.20210906.3.1

fuchsia/sdk/core/linux-amd64 old:https://chrome-infra-packages.appspot.com/p/fuchsia/sdk/core/linux-amd64/+/version:6.20210906.1.1 new:https://chrome-infra-packages.appspot.com/p/fuchsia/sdk/core/linux-amd64/+/version:6.20210906.3.1
fuchsia/sdk/core/mac-amd64 old:https://chrome-infra-packages.appspot.com/p/fuchsia/sdk/core/mac-amd64/+/version:6.20210906.1.1 new:https://chrome-infra-packages.appspot.com/p/fuchsia/sdk/core/mac-amd64/+/version:6.20210906.3.1

From: version:6.20210906.1.1
To: version:6.20210906.3.1
GitOrigin-RevId: 72c91f68647f6ab8340ed196f901d90bea839493
Change-Id: I5fb66bc0e4594e09bf5fbd7eeec8821488355288
diff --git a/jiri.lock b/jiri.lock
index 507b626..e9a6faa 100644
--- a/jiri.lock
+++ b/jiri.lock
@@ -263,13 +263,13 @@
     },
     {
         "package": "fuchsia/sdk/core/linux-amd64",
-        "version": "version:6.20210906.1.1",
-        "instance_id": "ExKaxwFaiC2Q0MPvXzFDXS6Zsm57fGinuw-0ku_sHkUC"
+        "version": "version:6.20210906.3.1",
+        "instance_id": "LRhOkqQK7_x8WUaxDv3uAxtkRpf3AR4j3GY9mqSdNq0C"
     },
     {
         "package": "fuchsia/sdk/core/mac-amd64",
-        "version": "version:6.20210906.1.1",
-        "instance_id": "c6Q9G-dYkW5Q1p6fYmj2JI6kKjG2wrF2yDZrQ0X7kEUC"
+        "version": "version:6.20210906.3.1",
+        "instance_id": "2hywa4CRB0Ze0_ndPyXN-ndBCj0n654r0WdIjsZdBPgC"
     },
     {
         "package": "fuchsia/starnix/android-image-amd64",
diff --git a/prebuilts b/prebuilts
index c9132ac..0f1a6a1 100644
--- a/prebuilts
+++ b/prebuilts
@@ -571,7 +571,7 @@
 
     <!-- Packages for SDK -->
     <package name="fuchsia/sdk/core/${platform}"
-             version="version:6.20210906.1.1"
+             version="version:6.20210906.3.1"
              platforms="linux-amd64,mac-amd64"
              path="prebuilt/sdk/core/{{.OS}}-{{.Arch}}"
              attributes="sdk"/>