vendor: update buildkit to v0.19.0-rc1

Signed-off-by: Tonis Tiigi <tonistiigi@gmail.com>

vendor/google.golang.org/grpc/internal/internal.go

@@ -183,7 +183,7 @@ var (
 
 	// GRPCResolverSchemeExtraMetadata determines when gRPC will add extra
 	// metadata to RPCs.
-	GRPCResolverSchemeExtraMetadata string = "xds"
+	GRPCResolverSchemeExtraMetadata = "xds"
 
 	// EnterIdleModeForTesting gets the ClientConn to enter IDLE mode.
 	EnterIdleModeForTesting any // func(*grpc.ClientConn)
@@ -191,6 +191,8 @@ var (
 	// ExitIdleModeForTesting gets the ClientConn to exit IDLE mode.
 	ExitIdleModeForTesting any // func(*grpc.ClientConn) error
 
+	// ChannelzTurnOffForTesting disables the Channelz service for testing
+	// purposes.
 	ChannelzTurnOffForTesting func()
 
 	// TriggerXDSResourceNotFoundForTesting causes the provided xDS Client to
@@ -203,11 +205,7 @@ var (
 
 	// UserSetDefaultScheme is set to true if the user has overridden the
 	// default resolver scheme.
-	UserSetDefaultScheme bool = false
-
-	// ShuffleAddressListForTesting pseudo-randomizes the order of addresses.  n
-	// is the number of elements.  swap swaps the elements with indexes i and j.
-	ShuffleAddressListForTesting any // func(n int, swap func(i, j int))
+	UserSetDefaultScheme = false
 
 	// ConnectedAddress returns the connected address for a SubConnState. The
 	// address is only valid if the state is READY.
@@ -235,7 +233,7 @@ var (
 //
 // The implementation is expected to create a health checking RPC stream by
 // calling newStream(), watch for the health status of serviceName, and report
-// it's health back by calling setConnectivityState().
+// its health back by calling setConnectivityState().
 //
 // The health checking protocol is defined at:
 // https://github.com/grpc/grpc/blob/master/doc/health-checking.md