[receiver/hostmetrics] Enable re-aggregation for process scraper (#46752)

### Description

Enable the re-aggregation feature for the `process` scraper within the
`hostmetrics` receiver.

**Changes made:**
- Added `reaggregation_enabled: true` to `metadata.yaml` for the process
scraper
- Added `requirement_level: recommended` to all metric attributes
(`context_switch_type`, `direction`, `paging_fault_type`, `state`)
- Ran `make generate` to update the generated metrics and configuration
files

### Link to tracking issues

Resolves #46623
Part of #46386

### Testing

- Ran `make generate` successfully
- Ran `make fmt` and `make lint` in the receiver module
- Executed `go test ./...` in the `processscraper` and parent
`hostmetricsreceiver` directories (all passed)

Author: iamjaeholee

.chloggen/enable-process-reaggregation.yaml

@@ -0,0 +1,5 @@
+change_type: enhancement
+component: receiver/hostmetrics
+note: Enable re-aggregation for process scraper
+issues: [46623]
+subtext: Enabled the reaggregation feature gate for the process scraper and set all metric attributes (context_switch_type, direction, paging_fault_type, state) with requirement_level recommended.

receiver/hostmetricsreceiver/internal/scraper/processscraper/internal/metadata/config.schema.yaml

@@ -11,34 +11,114 @@ $defs:
           enabled:
             type: boolean
             default: false
+          aggregation_strategy:
+            type: string
+            enum:
+              - "sum"
+              - "avg"
+              - "min"
+              - "max"
+            default: "sum"
+          attributes:
+            type: array
+            items:
+              type: string
+              enum:
+                - "type"
+            default:
+              - "type"
       process.cpu.time:
         description: "ProcessCPUTimeMetricConfig provides config for the process.cpu.time metric."
         type: object
         properties:
           enabled:
             type: boolean
             default: true
+          aggregation_strategy:
+            type: string
+            enum:
+              - "sum"
+              - "avg"
+              - "min"
+              - "max"
+            default: "sum"
+          attributes:
+            type: array
+            items:
+              type: string
+              enum:
+                - "state"
+            default:
+              - "state"
       process.cpu.utilization:
         description: "ProcessCPUUtilizationMetricConfig provides config for the process.cpu.utilization metric."
         type: object
         properties:
           enabled:
             type: boolean
             default: false
+          aggregation_strategy:
+            type: string
+            enum:
+              - "sum"
+              - "avg"
+              - "min"
+              - "max"
+            default: "avg"
+          attributes:
+            type: array
+            items:
+              type: string
+              enum:
+                - "state"
+            default:
+              - "state"
       process.disk.io:
         description: "ProcessDiskIoMetricConfig provides config for the process.disk.io metric."
         type: object
         properties:
           enabled:
             type: boolean
             default: true
+          aggregation_strategy:
+            type: string
+            enum:
+              - "sum"
+              - "avg"
+              - "min"
+              - "max"
+            default: "sum"
+          attributes:
+            type: array
+            items:
+              type: string
+              enum:
+                - "direction"
+            default:
+              - "direction"
       process.disk.operations:
         description: "ProcessDiskOperationsMetricConfig provides config for the process.disk.operations metric."
         type: object
         properties:
           enabled:
             type: boolean
             default: false
+          aggregation_strategy:
+            type: string
+            enum:
+              - "sum"
+              - "avg"
+              - "min"
+              - "max"
+            default: "sum"
+          attributes:
+            type: array
+            items:
+              type: string
+              enum:
+                - "direction"
+            default:
+              - "direction"
       process.handles:
         description: "ProcessHandlesMetricConfig provides config for the process.handles metric."
         type: object
@@ -81,6 +161,22 @@ $defs:
           enabled:
             type: boolean
             default: false
+          aggregation_strategy:
+            type: string
+            enum:
+              - "sum"
+              - "avg"
+              - "min"
+              - "max"
+            default: "sum"
+          attributes:
+            type: array
+            items:
+              type: string
+              enum:
+                - "type"
+            default:
+              - "type"
       process.signals_pending:
         description: "ProcessSignalsPendingMetricConfig provides config for the process.signals_pending metric."
         type: object