Add re_analysis environment varibles fields to soong_metrics

Test: Tested by following steps
1.m nothing: field is empty
2.USE_RBE=false m nothing: field log cc_wrapper and rbe_wrapper
3.USE_RBE=false m nothing: field is empty
Bug: 281922291

Change-Id: I1bbb324752b9a2dea1ff2c9df5817559d4cec3a6

ui/metrics/metrics.go

@@ -248,6 +248,13 @@ func (m *Metrics) SetBuildCommand(cmd []string) {
 	m.metrics.BuildCommand = proto.String(strings.Join(cmd, " "))
 }
 
+// AddChangedEnvironmentVariable adds the changed environment variable to
+// ChangedEnvironmentVariable field.
+func (m *Metrics) AddChangedEnvironmentVariable(ChangedEnvironmentVariable string) {
+	m.metrics.ChangedEnvironmentVariable = append(m.metrics.ChangedEnvironmentVariable,
+		ChangedEnvironmentVariable)
+}
+
 // Dump exports the collected metrics from the executed build to the file at
 // out path.
 func (m *Metrics) Dump(out string) error {