Upgrade vminitd API to use grpc-swift-2.

- No real notable API changes. The largest change
  code-wise is in Vminitd. The connection loop is
  set up immediately in the new API by calling
  runConnections() on the client, and this blocks
  until either the task it's running on is cancelled
  or beginGracefulShutdown is called. Because of
  this, either we'd have to modify our API to have
  VirtualMachineAgent implementations call some
  run() method, or we just put runConnections in
  an internal task on Vminitd. This change uses
  the latter approach as it's simpler.
- Updated dependencies to pick up latest protobuf
  and grpc-swift-2 fixes.
- ClientBootstrap.withConnectedSocket(fd).wait()
  registers the vsock fd with epoll/kqueue immediately.
  vminitd sends its HTTP/2 SETTINGS frame right away
  upon accepting the connection, so those bytes can
  arrive on the fd — and be read by NIO — before the
  gRPC pipeline is installed. With a bare pipeline,
  NIO has nowhere to send the bytes and discards them.
- Buffer until ClientConnectionHandler is in the
  pipeline so it can process the SETTINGS frame and
  fire .ready, then schedule delivery of the buffered
  data with assumeIsolatedUnsafeUnchecked().execute.

Co-authored-by: Danny Canter <danny_canter@apple.com>

Package.swift

@@ -36,17 +36,19 @@ let package = Package(
         .executable(name: "cctl", targets: ["cctl"]),
     ],
     dependencies: [
-        .package(url: "https://github.com/apple/swift-log.git", from: "1.0.0"),
-        .package(url: "https://github.com/apple/swift-argument-parser.git", from: "1.3.0"),
+        .package(url: "https://github.com/apple/swift-log.git", from: "1.10.1"),
+        .package(url: "https://github.com/apple/swift-argument-parser.git", from: "1.7.0"),
         .package(url: "https://github.com/apple/swift-collections.git", from: "1.1.4"),
         .package(url: "https://github.com/apple/swift-crypto.git", from: "3.0.0"),
-        .package(url: "https://github.com/grpc/grpc-swift.git", from: "1.26.0"),
-        .package(url: "https://github.com/apple/swift-protobuf.git", from: "1.29.0"),
+        .package(url: "https://github.com/grpc/grpc-swift-2.git", from: "2.3.0"),
+        .package(url: "https://github.com/grpc/grpc-swift-nio-transport.git", from: "2.4.4"),
+        .package(url: "https://github.com/grpc/grpc-swift-protobuf.git", from: "2.2.0"),
+        .package(url: "https://github.com/apple/swift-protobuf.git", from: "1.36.0"),
         .package(url: "https://github.com/apple/swift-nio.git", from: "2.80.0"),
+        .package(url: "https://github.com/apple/swift-nio-ssl.git", from: "2.36.0"),
         .package(url: "https://github.com/swift-server/async-http-client.git", from: "1.20.1"),
-        .package(url: "https://github.com/apple/swift-system.git", from: "1.4.0"),
+        .package(url: "https://github.com/apple/swift-system.git", from: "1.6.4"),
         .package(url: "https://github.com/swiftlang/swift-docc-plugin", from: "1.1.0"),
-        .package(url: "https://github.com/apple/swift-nio-ssl.git", from: "2.36.0"),
         .package(url: "https://github.com/facebook/zstd.git", exact: "1.5.7"),
     ],
     targets: [
@@ -57,8 +59,10 @@ let package = Package(
             name: "Containerization",
             dependencies: [
                 .product(name: "Logging", package: "swift-log"),
-                .product(name: "GRPC", package: "grpc-swift"),
                 .product(name: "SystemPackage", package: "swift-system"),
+                .product(name: "GRPCCore", package: "grpc-swift-2"),
+                .product(name: "GRPCNIOTransportHTTP2", package: "grpc-swift-nio-transport"),
+                .product(name: "GRPCProtobuf", package: "grpc-swift-protobuf"),
                 .product(name: "_NIOFileSystem", package: "swift-nio"),
                 "ContainerizationArchive",
                 "ContainerizationOCI",

Protobuf.Makefile

@@ -33,13 +33,13 @@ $(PROTOC):
 .PHONY: protoc-gen-swift
 protoc-gen-swift:
 	@$(SWIFT) build --product protoc-gen-swift
-	@$(SWIFT) build --product protoc-gen-grpc-swift
+	@$(SWIFT) build --product protoc-gen-grpc-swift-2
 
 .PHONY: protos
 protos: $(PROTOC) protoc-gen-swift
 	@echo Generating protocol buffers source code...
 	@$(PROTOC) Sources/Containerization/SandboxContext/SandboxContext.proto \
-		--plugin=protoc-gen-grpc-swift=$(BUILD_BIN_DIR)/protoc-gen-grpc-swift \
+		--plugin=protoc-gen-grpc-swift=$(BUILD_BIN_DIR)/protoc-gen-grpc-swift-2 \
 		--plugin=protoc-gen-swift=$(BUILD_BIN_DIR)/protoc-gen-swift \
 		--proto_path=Sources/Containerization/SandboxContext \
 		--grpc-swift_out="Sources/Containerization/SandboxContext" \