Add time unit for CriticalPathInfo's fields' name

Bug: 271526845
Test: check metrics
Change-Id: Ie7e133033371906b29caad16d0b6bcd238b9f8db
diff --git a/ui/metrics/metrics_proto/metrics.proto b/ui/metrics/metrics_proto/metrics.proto
index d95efa6..9f49dc7 100644
--- a/ui/metrics/metrics_proto/metrics.proto
+++ b/ui/metrics/metrics_proto/metrics.proto
@@ -321,10 +321,10 @@
 // CriticalPathInfo contains critical path nodes's information.
 // A critical path is a path determining the minimum time needed for the whole build given perfect parallelism.
 message CriticalPathInfo {
-  // Real time which the build system spent
-  optional uint64 elapsed_time = 1;
-  // The sum of execution time of the longest path from leave to the root
-  optional uint64 critical_path_time = 2;
+  // Real time which the build system spent in microseconds
+  optional uint64 elapsed_time_micros = 1;
+  // The sum of execution time of the longest path from leave to the root in microseconds
+  optional uint64 critical_path_time_micros = 2;
   // Detailed job information in a critical path.
   repeated JobInfo critical_path = 4;
   // Detailed job information for long running jobs (>30 seconds). These may or may not also be on a critical path.
@@ -332,8 +332,8 @@
 }
 
 message JobInfo {
-  // Real time which a job spent
-  optional uint64 elapsed_time = 1;
+  // Real time which a job spent in microseconds
+  optional uint64 elapsed_time_micros = 1;
   // Description of a job
   optional string job_description = 2;
 }