Add provision job metadata to identify prebuilds

Signed-off-by: Danny Kopping <danny@coder.com>

coderd/wsbuilder/wsbuilder.go

@@ -72,6 +72,7 @@ type Builder struct {
 	lastBuildJob                 *database.ProvisionerJob
 	parameterNames               *[]string
 	parameterValues              *[]string
+	prebuild                     bool
 
 	verifyNoLegacyParametersOnce bool
 }
@@ -168,6 +169,12 @@ func (b Builder) RichParameterValues(p []codersdk.WorkspaceBuildParameter) Build
 	return b
 }
 
+func (b Builder) MarkPrebuild() Builder {
+	// nolint: revive
+	b.prebuild = true
+	return b
+}
+
 // SetLastWorkspaceBuildInTx prepopulates the Builder's cache with the last workspace build.  This allows us
 // to avoid a repeated database query when the Builder's caller also needs the workspace build, e.g. auto-start &
 // auto-stop.
@@ -295,6 +302,7 @@ func (b *Builder) buildTx(authFunc func(action policy.Action, object rbac.Object
 	input, err := json.Marshal(provisionerdserver.WorkspaceProvisionJob{
 		WorkspaceBuildID: workspaceBuildID,
 		LogLevel:         b.logLevel,
+		IsPrebuild:       b.prebuild,
 	})
 	if err != nil {
 		return nil, nil, nil, BuildError{