VOL-4878:BBSIM  change to test the rxPower fetch changes at open olt adaptor

Change-Id: I02eb8c016b797c70a15f31c3b4bf98efd78c6c86
diff --git a/internal/bbsim/devices/olt.go b/internal/bbsim/devices/olt.go
index bbe49bc..587a2ed 100644
--- a/internal/bbsim/devices/olt.go
+++ b/internal/bbsim/devices/olt.go
@@ -1671,7 +1671,8 @@
 }
 
 func (o *OltDevice) GetPonRxPower(ctx context.Context, in *openolt.Onu) (*openolt.PonRxPowerData, error) {
-	return &openolt.PonRxPowerData{}, nil
+	//VOL-4878:Hardcoding the power levels for testing  as BBSIM is a simulator
+	return &openolt.PonRxPowerData{IntfId: in.IntfId, OnuId: in.OnuId, Status: "success", FailReason: 0, RxPowerMeanDbm: -6}, nil
 }
 
 func (o *OltDevice) GetGemPortStatistics(ctx context.Context, in *openolt.OnuPacket) (*openolt.GemPortStatistics, error) {