Collect FORCE_USE_GOMA environment variable as a metric.

FORCE_USE_GOMA is needed to be collected as a metric for the
deprecation of GOMA on Android builds.

Bug: b/169423400
Test: m nothing, ran printproto command
Change-Id: I12300389f1f27239d8f21875d1b6e4ad069d95d7

ui/build/config.go

@@ -298,8 +298,9 @@ func storeConfigMetrics(ctx Context, config Config) {
 	}
 
 	b := &smpb.BuildConfig{
-		UseGoma: proto.Bool(config.UseGoma()),
-		UseRbe:  proto.Bool(config.UseRBE()),
+		ForceUseGoma: proto.Bool(config.ForceUseGoma()),
+		UseGoma:      proto.Bool(config.UseGoma()),
+		UseRbe:       proto.Bool(config.UseRBE()),
 	}
 	ctx.Metrics.BuildConfig(b)
 }