apply review suggestions

Author: mmat11

auditbeat/_meta/fields.common.yml

@@ -66,7 +66,7 @@
         description: Process command.
 
       - name: pid
-        type: integer
+        type: long
         description: PID.
 
       - name: user.id

auditbeat/module/file_integrity/event.go

@@ -135,7 +135,6 @@ type Event struct {
 	Hashes        map[HashType]Digest `json:"hash,omitempty"`        // File hashes.
 	ParserResults mapstr.M            `json:"file,omitempty"`        // Results from running file parsers.
 	Process       *Process            `json:"process,omitempty"`     // Process data. Available only on Linux when using the eBPF backend.
-	// TODO(matt): ContainerID string `json:"container_id,omitempty"` // Unique container ID. Available only on Linux when using the eBPF backend.
 
 	// Metadata
 	rtt        time.Duration // Time taken to collect the info.