Add SoongExecutionMetrics to ninja run

This adds metrics for partial compilation to Soong.

- Soong_ui names the directory SOONG_METRICS_AGGREGATION_DIR, which it
  empties before each ninja run.
- Find_input_delta writes metrics there
- At the end of the build, Soong_ui aggregates the metrics that were
  written to generate the aggregated metrics.

Bug: b/376287012
Test: Manual, TH
Change-Id: I123df654f5b963fcd213b5c4d815173051f5d72e
diff --git a/ui/build/context.go b/ui/build/context.go
index fd20e26..69e5f96 100644
--- a/ui/build/context.go
+++ b/ui/build/context.go
@@ -18,6 +18,7 @@
 	"context"
 	"io"
 
+	"android/soong/ui/execution_metrics"
 	"android/soong/ui/logger"
 	"android/soong/ui/metrics"
 	soong_metrics_proto "android/soong/ui/metrics/metrics_proto"
@@ -33,7 +34,8 @@
 	context.Context
 	logger.Logger
 
-	Metrics *metrics.Metrics
+	Metrics          *metrics.Metrics
+	ExecutionMetrics *execution_metrics.ExecutionMetrics
 
 	Writer io.Writer
 	Status *status.Status