fix PAPI conversion (#18722)

Author: AlexTugarev

components/gitpod-protocol/go/gitpod-service.go

@@ -2251,7 +2251,7 @@ type Project struct {
 }
 
 type ProjectSettings struct {
-	EnablePrebuilds              bool                      `json:"enablePrebuilds,omitempty"`
+	EnablePrebuilds              *bool                     `json:"enablePrebuilds,omitempty"`
 	UseIncrementalPrebuilds      bool                      `json:"useIncrementalPrebuilds,omitempty"`
 	UsePersistentVolumeClaim     bool                      `json:"usePersistentVolumeClaim,omitempty"`
 	KeepOutdatedPrebuildsRunning bool                      `json:"keepOutdatedPrebuildsRunning,omitempty"`

components/public-api/gitpod/experimental/v1/projects.proto

@@ -47,7 +47,7 @@ message PrebuildSettings {
     bool keep_outdated_prebuilds_running = 2;
     bool use_previous_prebuilds = 3;
     int32 prebuild_every_nth = 4;
-    bool enable_prebuilds = 5;
+    optional bool enable_prebuilds = 5;
 }
 
 message WorkspaceSettings {