[roll] Roll sdk-core packages to version:6.20210917.3.1

fuchsia/sdk/core/linux-amd64 old:https://chrome-infra-packages.appspot.com/p/fuchsia/sdk/core/linux-amd64/+/version:6.20210917.1.1 new:https://chrome-infra-packages.appspot.com/p/fuchsia/sdk/core/linux-amd64/+/version:6.20210917.3.1
fuchsia/sdk/core/mac-amd64 old:https://chrome-infra-packages.appspot.com/p/fuchsia/sdk/core/mac-amd64/+/version:6.20210917.1.1 new:https://chrome-infra-packages.appspot.com/p/fuchsia/sdk/core/mac-amd64/+/version:6.20210917.3.1

From: version:6.20210917.1.1
To: version:6.20210917.3.1
GitOrigin-RevId: 34bd2b60d784cdb619dc87b780246100245fcee9
Change-Id: Iec8d500df9e835211d78527272e40f375e0537d5
diff --git a/jiri.lock b/jiri.lock
index 8b34efd..e267d27 100644
--- a/jiri.lock
+++ b/jiri.lock
@@ -263,13 +263,13 @@
     },
     {
         "package": "fuchsia/sdk/core/linux-amd64",
-        "version": "version:6.20210917.1.1",
-        "instance_id": "If8qUioWSekPLPgRkrWAqLI7wMo1Vke4GpmQE55G7E8C"
+        "version": "version:6.20210917.3.1",
+        "instance_id": "e4mEPudr4bO455DyD56mlzKEkMZW1MDIyiee10UTVQkC"
     },
     {
         "package": "fuchsia/sdk/core/mac-amd64",
-        "version": "version:6.20210917.1.1",
-        "instance_id": "Y-IDWgql1lq1Z2e1ZbDb6Di7F_oOS1ut7gAApIIlmwMC"
+        "version": "version:6.20210917.3.1",
+        "instance_id": "ig96PZ9uuCdtKt0-_1lhYHIB6ot7o9vYVpYh-JHPpXIC"
     },
     {
         "package": "fuchsia/starnix/android-image-amd64",
diff --git a/prebuilts b/prebuilts
index 2f4ad29..54a3b7f 100644
--- a/prebuilts
+++ b/prebuilts
@@ -571,7 +571,7 @@
 
     <!-- Packages for SDK -->
     <package name="fuchsia/sdk/core/${platform}"
-             version="version:6.20210917.1.1"
+             version="version:6.20210917.3.1"
              platforms="linux-amd64,mac-amd64"
              path="prebuilt/sdk/core/{{.OS}}-{{.Arch}}"
              attributes="sdk"/>