healthd: return battery status property

Bug: 34198239
Change-Id: Ib0f312c15eb75ba7482f4f0b3f30ba2feae2c209
diff --git a/healthd/BatteryMonitor.cpp b/healthd/BatteryMonitor.cpp
index 369a022..4007203 100644
--- a/healthd/BatteryMonitor.cpp
+++ b/healthd/BatteryMonitor.cpp
@@ -348,6 +348,7 @@
 
 status_t BatteryMonitor::getProperty(int id, struct BatteryProperty *val) {
     status_t ret = BAD_VALUE;
+    std::string buf;
 
     val->valueInt64 = LONG_MIN;
 
@@ -400,6 +401,15 @@
         }
         break;
 
+    case BATTERY_PROP_BATTERY_STATUS:
+        if (mAlwaysPluggedDevice) {
+            val->valueInt64 = BATTERY_STATUS_CHARGING;
+        } else {
+            val->valueInt64 = getChargeStatus();
+        }
+        ret = NO_ERROR;
+        break;
+
     default:
         break;
     }