[roll] Roll sdk-core CIPD packages:

fuchsia/sdk/core/linux-amd64 old:https://chrome-infra-packages.appspot.com/p/fuchsia/sdk/core/linux-amd64/+/version:0.20201212.2.1 new:https://chrome-infra-packages.appspot.com/p/fuchsia/sdk/core/linux-amd64/+/version:0.20201212.3.1
fuchsia/sdk/core/mac-amd64 old:https://chrome-infra-packages.appspot.com/p/fuchsia/sdk/core/mac-amd64/+/version:0.20201212.2.1 new:https://chrome-infra-packages.appspot.com/p/fuchsia/sdk/core/mac-amd64/+/version:0.20201212.3.1

From: version:0.20201212.2.1
To: version:0.20201212.3.1
GitOrigin-RevId: 4982985ae9f955a6bf0d5e4c76c5f20686cfd1cb
Change-Id: I45d815577fa57aeb59db8fda6663a5a603eb1466
diff --git a/jiri.lock b/jiri.lock
index 3d04123..55c69cf 100644
--- a/jiri.lock
+++ b/jiri.lock
@@ -243,13 +243,13 @@
     },
     {
         "package": "fuchsia/sdk/core/linux-amd64",
-        "version": "version:0.20201212.2.1",
-        "instance_id": "9g4mu6miYcS1BhdZaop3LnyKubWBxeM7Uug3wP2CuOYC"
+        "version": "version:0.20201212.3.1",
+        "instance_id": "WMAneAIxxBQ53tG1Hu4DN2ZHJiCbwABYMYohV1hhiwAC"
     },
     {
         "package": "fuchsia/sdk/core/mac-amd64",
-        "version": "version:0.20201212.2.1",
-        "instance_id": "4iOG5W4xldvLIhi5fTwbKjfMgneySMCIIbS0EGtI12cC"
+        "version": "version:0.20201212.3.1",
+        "instance_id": "oaYzoSktIMMhqz5ynRPS_JhXqQ9N_KEWVYpoqyAlvyMC"
     },
     {
         "package": "fuchsia/test_data/debug/sample_core",
diff --git a/prebuilts b/prebuilts
index 513b573..9358186 100644
--- a/prebuilts
+++ b/prebuilts
@@ -538,7 +538,7 @@
 
     <!-- Packages for SDK -->
     <package name="fuchsia/sdk/core/${platform}"
-             version="version:0.20201212.2.1"
+             version="version:0.20201212.3.1"
              platforms="linux-amd64,mac-amd64"
              path="prebuilt/sdk/core/{{.OS}}-{{.Arch}}"
              attributes="sdk"/>