[release] Update checked-in SDKs to 2.19.0

Don't upload riscv64 checked-in SDKs unless a dev version is specified.
This means gclient will not have a checked-in SDK for riscv64 checkouts
unless pinned to a dev version of the checked-in SDK.

Change-Id: I718c022228a8430d5d6b27f8a3d0f728b616c553
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/279707
Commit-Queue: Alexander Thomas <athom@google.com>
Reviewed-by: Ryan Macnak <rmacnak@google.com>
Reviewed-by: William Hesse <whesse@google.com>

DEPS

@@ -47,7 +47,7 @@ vars = {
 
   # Checked-in SDK version. The checked-in SDK is a Dart SDK distribution in a
   # cipd package used to run Dart scripts in the build and test infrastructure.
-  "sdk_tag": "version:2.19.0-374.0.dev",
+  "sdk_tag": "version:2.19.0",
 
   # co19 is a cipd package. Use update.sh in tests/co19[_2] to update these
   # hashes.

tools/sdks/update.sh

@@ -51,15 +51,17 @@ cipd create \
   -ref $channel
 rm -rf sdk
 
-gsutil.py cp "gs://dart-archive/channels/$channel/release/$1/sdk/dartsdk-linux-riscv64-release.zip" .
-unzip -q dartsdk-linux-riscv64-release.zip -d sdk
-cipd create \
-  -name dart/dart-sdk/linux-riscv64 \
-  -in sdk \
-  -install-mode copy \
-  -tag version:$1 \
-  -ref $channel
-rm -rf sdk
+if [ "$channel" = "dev" ]; then
+  gsutil.py cp "gs://dart-archive/channels/$channel/release/$1/sdk/dartsdk-linux-riscv64-release.zip" .
+  unzip -q dartsdk-linux-riscv64-release.zip -d sdk
+  cipd create \
+    -name dart/dart-sdk/linux-riscv64 \
+    -in sdk \
+    -install-mode copy \
+    -tag version:$1 \
+    -ref $channel
+  rm -rf sdk
+fi
 
 gsutil.py cp "gs://dart-archive/channels/$channel/release/$1/sdk/dartsdk-macos-x64-release.zip" .
 unzip -q dartsdk-macos-x64-release.zip -d sdk