Add telemetry to track use of experimental.use_legacy_run_as (#3321)

## Why
Since we'll soon be adding support for run_as for DLT pipelines we can
remove support for the legacy mode.
#3307

Tracking usage will inform us of the impact from removing this option. 

## Tests
New test and existing ones.

Author: shreyas-goenka

acceptance/bundle/paths/fallback_metric/output.txt

@@ -14,6 +14,10 @@ Deployment complete!
 
 >>> cat out.requests.txt
 [
+  {
+    "key": "experimental.use_legacy_run_as",
+    "value": false
+  },
   {
     "key": "presets_name_prefix_is_set",
     "value": false
@@ -40,6 +44,10 @@ Deployment complete!
   }
 ]
 [
+  {
+    "key": "experimental.use_legacy_run_as",
+    "value": false
+  },
   {
     "key": "presets_name_prefix_is_set",
     "value": false

acceptance/bundle/telemetry/deploy-compute-type/output.txt

@@ -13,6 +13,10 @@ Deployment complete!
 
 >>> cat out.requests.txt
 [
+  {
+    "key": "experimental.use_legacy_run_as",
+    "value": false
+  },
   {
     "key": "presets_name_prefix_is_set",
     "value": false
@@ -39,6 +43,10 @@ Deployment complete!
   }
 ]
 [
+  {
+    "key": "experimental.use_legacy_run_as",
+    "value": false
+  },
   {
     "key": "presets_name_prefix_is_set",
     "value": false

acceptance/bundle/telemetry/deploy-experimental/databricks.yml

@@ -0,0 +1,14 @@
+experimental:
+  use_legacy_run_as: true
+
+run_as:
+  user_name: abcd
+
+resources:
+  jobs:
+    foo:
+      tasks:
+        - task_key: task1
+          spark_python_task:
+            python_file: /Workspace/test.py
+          existing_cluster_id: hjkl

acceptance/bundle/telemetry/deploy-experimental/out.test.toml

@@ -0,0 +1,5 @@
+Local = true
+Cloud = false
+
+[EnvMatrix]
+  DATABRICKS_CLI_DEPLOYMENT = ["terraform", "direct-exp"]

acceptance/bundle/telemetry/deploy-experimental/output.txt

@@ -0,0 +1,44 @@
+
+>>> [CLI] bundle deploy
+Warning: You are using the legacy mode of run_as. The support for this mode is experimental and might be removed in a future release of the CLI. In order to run the DLT pipelines in your DAB as the run_as user this mode changes the owners of the pipelines to the run_as identity, which requires the user deploying the bundle to be a workspace admin, and also a Metastore admin if the pipeline target is in UC.
+  at experimental.use_legacy_run_as
+  in databricks.yml:4:22
+
+Uploading bundle files to /Workspace/Users/[USERNAME]/.bundle/test-bundle/default/files...
+Deploying resources...
+Updating deployment state...
+Deployment complete!
+
+>>> cat out.requests.txt
+{
+  "bool_values": [
+    {
+      "key": "experimental.use_legacy_run_as",
+      "value": true
+    },
+    {
+      "key": "presets_name_prefix_is_set",
+      "value": false
+    },
+    {
+      "key": "skip_artifact_cleanup",
+      "value": false
+    },
+    {
+      "key": "python_wheel_wrapper_is_set",
+      "value": false
+    },
+    {
+      "key": "has_serverless_compute",
+      "value": false
+    },
+    {
+      "key": "has_classic_job_compute",
+      "value": false
+    },
+    {
+      "key": "has_classic_interactive_compute",
+      "value": true
+    }
+  ]
+}

acceptance/bundle/telemetry/deploy-experimental/script

@@ -0,0 +1,5 @@
+trace $CLI bundle deploy
+
+trace cat out.requests.txt | jq 'select(has("path") and .path == "/telemetry-ext") | .body.protoLogs[] | fromjson | .entry.databricks_cli_log.bundle_deploy_event.experimental | {bool_values}'
+
+rm out.requests.txt

acceptance/bundle/telemetry/deploy-name-prefix/custom/output.txt

@@ -8,6 +8,10 @@ Deployment complete!
 >>> cat out.requests.txt
 {
   "bool_values": [
+    {
+      "key": "experimental.use_legacy_run_as",
+      "value": false
+    },
     {
       "key": "presets_name_prefix_is_set",
       "value": true

acceptance/bundle/telemetry/deploy-name-prefix/mode-development/output.txt

@@ -8,6 +8,10 @@ Deployment complete!
 >>> cat out.requests.txt
 {
   "bool_values": [
+    {
+      "key": "experimental.use_legacy_run_as",
+      "value": false
+    },
     {
       "key": "presets_name_prefix_is_set",
       "value": true

acceptance/bundle/telemetry/deploy/out.telemetry.txt

@@ -42,6 +42,10 @@
           "lookup_variable_count": 0,
           "target_count": 1,
           "bool_values": [
+            {
+              "key": "experimental.use_legacy_run_as",
+              "value": false
+            },
             {
               "key": "presets_name_prefix_is_set",
               "value": false

bundle/config/mutator/resourcemutator/run_as.go

@@ -181,6 +181,9 @@ func setPipelineOwnersToRunAsIdentity(b *bundle.Bundle) {
 }
 
 func (m *setRunAs) Apply(_ context.Context, b *bundle.Bundle) diag.Diagnostics {
+	// Track the use of the legacy run_as mode.
+	b.Metrics.AddBoolValue("experimental.use_legacy_run_as", b.Config.Experimental != nil && b.Config.Experimental.UseLegacyRunAs)
+
 	// Mutator is a no-op if run_as is not specified in the bundle
 	if b.Config.Value().Get("run_as").Kind() == dyn.KindInvalid {
 		return nil