healthd: Add average current property

Change-Id: Ibc901fe1b550c0d72095ef5590e2db8962d1a7b2
diff --git a/healthd/healthd.cpp b/healthd/healthd.cpp
index 1719c22..f7c79c4 100644
--- a/healthd/healthd.cpp
+++ b/healthd/healthd.cpp
@@ -49,6 +49,7 @@
     .batteryTemperaturePath = String8(String8::kEmptyString),
     .batteryTechnologyPath = String8(String8::kEmptyString),
     .batteryCurrentNowPath = String8(String8::kEmptyString),
+    .batteryCurrentAvgPath = String8(String8::kEmptyString),
     .batteryChargeCounterPath = String8(String8::kEmptyString),
 };